Everyone over the age of 50 should be given statins because the “cholesterol-busting” drugs reduce the risk of a heart attack even in healthy people, according to the Daily Telegraph and many other papers today.

The story is based on a systematic review of 27 studies looking at the effect of lowering low-density lipoprotein cholesterol (LDL, the “bad” cholesterol) using statin therapy in 175,000 individuals. It found that for every 1.0 mmol/L reduction in cholesterol, taking statins reduced the risk of heart attacks, strokes and other “major vascular events”  by about a fifth (21%), even among those without existing vascular disease or at low risk of developing it.

Current guidelines recommend prescribing statins for people who have at least a 20% chance of developing cardiovascular disease within 10 years. Doctors normally calculate this risk by looking at a range of factors including the patient’s age, blood pressure, cholesterol levels, whether they smoke and whether they have diabetes.

This large review of studies suggests the cholesterol-lowering drugs are suitable for those without existing heart or vascular disease and those who are not considered at high risk of developing it. The 21% reduction in risk of heart disease and stroke sounds impressive.

However, it’s worth noting that the number of people who stand to benefit from statins gets smaller as the risk threshold for treatment is reduced. For example, one thousand people at low risk would need to be treated (have a 1 mmol/L reduction in bad cholesterol) for five years in order for 11 of them to benefit. This suggests that someone at low risk may wish to consider whether the possible benefit of taking statins would outweigh the inconvenience.

An accompanying editorial argues that the current guidelines should be revised to use age as an indicator for statins (over 50 years old), rather than expensive screening tests. The commentary forms part of a running debate as to whether middle-aged people without any known risk of cardiovascular disease should be “medicated”, and if so, how much (whether with statins, aspirin or a “polypill”, as previously suggested).

 

Where did the story come from?

The study was carried out by researchers from Oxford University and the University of Sydney. It was funded by several institutions including the British Heart Foundation, the UK Medical Research Council and Cancer Research UK.
The study was published in the peer-reviewed medical journal, The Lancet.

The study – in particular the commentary arguing for all over 50s to take statins - was covered widely and accurately in most of the media.

 

What kind of research was this?

This was a meta-analysis of individual patient data from 27 trials looking at the effects of lowering LDL cholesterol with statin therapy, including trials of those without vascular disease or at low risk of cardiovascular disease.

The authors pointed out that their previous analysis of studies suggested that statin therapy to reduce LDL cholesterol in people without a history of vascular disease ultimately reduced their risk of heart attacks and strokes by about a fifth. However, uncertainty remains as to whether statins have an overall “net benefit” in this group, given that they are at low risk to begin with. The authors said that at least half of all heart attacks and strokes (vascular events) occur among individuals without previous disease.

The authors said they have now taken individual patient data from each trial within the database, allowing a more complete assessment of the effects of lowering LDL cholesterol in low-risk individuals.

 

What did the research involve?

The researchers conducted a meta-analysis of data from 175,000 participants in 27 randomised trials, to explore the effects of lowering LDL cholesterol with statin therapy. Trials were included if:

• They included at least one treatment where the main effect was to lower LDL cholesterol.
• There were no other differences in treating risk factors.
• At least 1,000 participants were recruited for a duration of at least two years’ treatment.

The “major vascular events” they looked at included heart attacks and deaths from heart attack, strokes and coronary revascularisations (surgery to unblock coronary arteries). They also looked at rates of cancer and the cause of any death that occurred.

They grouped the participants into five categories depending on their risk of a vascular event within five years and compared those taking a statin with control groups or with group taking a lower-dose statin. The risk categories were:

• less than 5%
• 5% to less than 10%
• 10% to less than 20%
• 20% to less than 30%
• 30% or more

The researchers analysed the results using standard statistical methods.

 

What were the basic results?

The researchers found that:

• Reducing LDL cholesterol with a statin reduced the risk of major vascular events (relative risk 0.79, 95% confidence interval 0.77 to 0.81 per 1.0 mmol/L reduction), largely irrespective of age, sex, baseline LDL cholesterol or previous vascular disease, and of vascular mortality and all-cause mortality.
• The reduction in major vascular events was at least as big in people in the two lowest risk categories as those in the higher risk categories.
• For stroke, the reduction in risk in participants with a 5-year risk of major vascular events lower than 10% (relative risk per 1.0 mmol/L LDL cholesterol reduction 0.76, 99% confidence interval 0.61 to 0.95) was also similar to that seen in higher-risk categories.
• In participants without a history of vascular disease, statins reduced the risks of deaths from vascular disease and any other cause (relative risk 0.91, 95% confidence interval 0.85 to 0.97).

There was no evidence that reducing LDL cholesterol with a statin increased cancer incidence, death from cancer, or deaths from other non-vascular causes.

 

How did the researchers interpret the results?

The researchers calculated that in individuals with a five-year risk of major vascular events lower than 10%, each 1 mmol/L reduction in LDL cholesterol produced an absolute reduction in major vascular events of about 11 per 1,000 over five years.  They said this benefit “greatly exceeds any known hazards of statin therapy”.

They also pointed out that, under present guidelines, such individuals would typically not be regarded as suitable for statin therapy.

They concluded: "The present report shows that statins are indeed both effective and safe for people with a five-year risk of major vascular events lower than 10% who would typically not be judged suitable for statin treatment … and, therefore, suggests that treatment guidelines might need to be reconsidered."

 

Conclusion

Current guidelines recommend statins for people who have a 20% or greater chance of developing cardiovascular disease within 10 years. This large review of studies, which is a further assessment of previous research, suggests they may also benefit those without existing cardiovascular disease and those who are not considered at high risk of developing it.  However, the individual benefit for those at low risk may be small.

Although the study looked at whether statins increased the risk of cancer and death from other causes, it did not include possible adverse effects. Statins are safe drugs that have been associated with a small risk of side effects. As the authors stated, the risk of side effects when giving statins to everyone over the age of 50 would have to be taken into account when calculating the overall benefit.

The current guidelines on statin therapy from the National Institute of Health and Clinical Excellence (NICE) are reportedly to be updated soon, at which point NICE will take this and any other new evidence into account.

There is good existing evidence that a healthy lifestyle (including regular exercise, stopping smoking and a healthy diet) are also important factors in cardiovascular health. This study helps to answer previous uncertainty about which apparently healthy individuals could benefit from taking statins.

Links To The Headlines

Give statins to everyone over 50. Daily Express, May 17 2012

NHS 'should consider giving statins to healthy people'. BBC News, May 17 2012

Statins could benefit health of millions. The Guardian, May 17 2012

All over 50s should be taking statins. The Daily Telegraph, May 17 2012

Statins 'could benefit the healthy'. The Independent, May 17 2012

Why EVERYONE over 50 needs to be taking statins: Cholesterol-busting pills cut risk of heart attack or stroke. Daily Mail, May 17 2012

Links To Science

Cholesterol Treatment Trialists' Collaborators. The effects of lowering LDL cholesterol with statin therapy in people at low risk of vascular disease: meta-analysis of individual data from 27 randomised trials. The Lancet. Published online May 17 2012

The Daily Telegraph boldly and erroneously reports that “women really do have a 'gaydar' which allows them to tell someone's sexuality 'in the blink of an eye'”, while the Sun informs us that “most people have a ‘gaydar’”.

This story is based on a study that looked at how accurately people can judge someone’s sexual orientation from their face. In two experiments, researchers investigated how accurately US college students judged whether someone was ‘gay’ or ‘straight’ after quickly glancing at a photo. The research found that students were able correctly to determine sexual orientation slightly more often than could be put down to chance. It found that students were able to identify a woman’s sexuality correctly 65% of the time, and a man’s sexuality correctly 57% of the time. The research suggests that people may unconsciously make judgements about sexual orientation when seeing a face for the first time.

Based on this study, the headline that "most people have a gaydar" is misleading. Limited conclusions can be drawn from this small and highly artificial study as accuracy was only just better than chance. In order to draw firm conclusions, larger studies that include people of different ages and from different backgrounds are required. The type of study used does not consider the influence of other factors that could contribute to how a person makes quick decisions about another person’s sexuality and it is not clear whether quick judgements about a person’s sexuality occur in real life.

It is important to note that guessing another person’s sexuality may be a sensitive area. This study does not explore the consequences of making quick judgements about another person’s sexuality. It does show that a subjective snap judgement of someone’s sexuality based on their appearance has a good chance of being wrong. Making decisions on such snap judgements is ill advised, even if you think you have a great ‘gaydar’.

 

Where did the story come from?

The study was carried out by researchers from the University of Washington and Cornell University, US. It was funded by grants from the US Association for Psychological Science, Cornell University’s Einhorn Family Charitable Trust Endowment, the Cognitive Science Program, and the College of Arts and Sciences. The study was published in the peer-reviewed online journal Public Library of Science (PLoS) ONE.

This study was picked up by a variety of papers and online media and most had attention-grabbing headlines like “gaydar exists”. Apart from the overblown headlines, the Daily Mirror and the Sun reported the details of the study accurately. However, both The Daily Telegraph and Metro misleadingly suggest that the research showed women could judge another person’s sexuality better than men. In fact, the research showed that people were better able to judge whether women were gay or straight, not that women were better able to judge sexuality.

 

What kind of research was this?

This was an observational study that aimed to investigate how people make a judgement about someone’s sexuality based on their face. This was a relatively small study that only investigated the judgements of college students from one US university.

Previous research has indicated that there are two ways in which a person perceives a human face – “featural processing” and “configural processing”:

• featural processing involves looking at facial features such as the nose or eyes
• configural processing involves looking at the relationship between facial features, such as the distance between the eyes

 

What did the research involve?

Researchers undertook two experiments. In the first experiment, they recruited 24 University of Washington students (19 women) in exchange for extra course credits. The students viewed 96 photos of young adult men and women who identified themselves as gay or straight. The participants categorised each face as either straight or gay as quickly and accurately as possible. The photographs were of “white-looking” faces of people reportedly aged 18–29 gathered from Facebook. They included individuals living in 11 major US cities. Photographs were digitally altered to remove hairstyles so that only faces were visible. Faces with facial hair, make-up, glasses and piercings were excluded so as to limit any potential prejudice. Photos were flashed up on a screen for 50 milliseconds (approximately a third of the time it takes to blink the eye).

In the second experiment, comprising 129 students (92 women and 37 men), participants were randomly assigned to judge faces that were either upright or upside down. This experiment was designed to judge whether ability to read sexual orientation depends on configural processing (the relationship between features).

Results were analysed using statistical methods to determine whether the results were achieved by accurate judgement or whether similar results could have occurred by chance.

 

What were the basic results?

The main finding of this small study was that students were able to determine sexual orientation from glancing at a photo more often than could be put down to chance. (By chance alone it is assumed that people would be correct 50% of the time, like the toss of a coin.) It found that, in the first experiment students were able to identify the sexuality of women’s faces 65% of the time, while they were correct 57% of the time when viewing men’s faces. In the second experiment, the researchers found that when the picture was glanced at upside down, the success rate was less accurate (61% for women and 53% for men).

The researchers report that the increase in accuracy for judging upright faces suggests that the ability to read sexual orientation from men’s and women’s faces relies on configural face processing (relationships of facial features) as well as featural face processing (facial features). They say the results also indicate that reading sexual orientation from faces of women is easier than from faces of men.

 

How did the researchers interpret the results?

The researchers conclude that configural face processing significantly affects a person’s perception of sexual orientation and that sexual orientation is easier to detect in women’s faces than men’s faces.

The lead researcher, Joshua Tabak, is reported as having said that "we were surprised that participants were above-chance judging sexual orientation based on upside down photos flashed for just 50 milliseconds, about a third the time of an eyeblink". He went on to say that “people of older generations or cultures where homosexuality is not recognised may find it harder to make ‘gaydar’ judgments”.

 

Conclusion

This small study, carried out in highly artificial conditions, shows that students were able to judge sexuality with greater accuracy than could be put down to chance, and that women’s sexuality was judged more accurately than men’s sexuality. Despite these findings, the study should not be misinterpreted to mean that women are better at accurately judging a person's sexuality than men.

The participants' judgement was only just better than the results that could have been expected to have been achieved by chance and larger studies that include people of different ages and backgrounds are required to verify these results.

It is important to note that, in this study, students were instructed to make forced decisions about a person’s sexuality. It is unclear whether these quick decisions are made in real life situations. In addition, this study does not explore the consequences of making quick judgements about another person’s sexuality.

Guessing another person’s sexuality can be a sensitive area. This study highlights the importance of not making snap decisions based on your own subjective judgement of someone else’s sexuality because of the high chance that you may be wrong.

It is also worth noting the inaccurate reporting in both The Telegraph’s and Metro’s stories on this research. While the Mirror and the Sun also featured exaggerated headlines, their reporters did a better job of presenting the research.

Analysis by Bazian.

Links To The Headlines

Gaydar exists: we can tell who is gay and who is straight in the blink of an eye. Daily Mirror, May 18 2012

Gaydar quick as eye's blink. The Sun, May 18 2012

Study claims females really do have a 'gaydar'. Metro, May 18 2012

Women really do have a 'gaydar'. The Daily Telegraph, May 18 2012

Links To Science

Tabak JA, Zayas V. The Roles of Featural and Configural Face Processing in Snap Judgments of Sexual Orientation. PLoS One. Published online May 16 2012

“NHS ban on pill to treat prostate cancer is lifted,” the Daily Express has said, while the Daily Mail has warned that a “prostate cancer wonder drug” was set for approval “south of border but turned down by Scotland”. The stories focus on the fact that the prostate cancer drug abiraterone may soon be available on the NHS in certain circumstances.

These stories are based on a revised decision on draft guidance published by The National Institute for Health and Clinical Excellence (NICE), which makes recommendations about which treatments should be available on the NHS in England and Wales. It recommends that abiraterone (brand name Zytiga) be made available for the treatment of advanced prostate cancer that has not responded to chemotherapy.

Previous draft NICE guidance published in February rejected the use of abiraterone, concluding that it was not cost-effective. The new draft guidance has reconsidered this decision following an offer from the drug manufacturer to make the drug available at a lower price to the NHS.

The Scottish Medicines Consortium (SMC), which advises NHS bodies in Scotland about the status of new treatments, published guidance in March that rejected making abiraterone available. The SMC is currently considering further evidence and is due to publish further guidance this summer.

 

What is abiraterone used for?

Abiraterone is a type of hormone therapy for cancer that has spread beyond the prostate to other parts of the body (metastatic prostate cancer). It is a tablet taken once a day in combination with a steroid drug (prednisolone or prednisone), which reduces inflammation.

Hormone treatments for prostate cancer aim to block the production of certain male hormones (androgens) that stimulate prostate cancers to grow. Although there are already hormone treatments for prostate cancer, the new drug works in a different way by blocking cytochrome P17, an enzyme that enables the body to make androgens.

Abiraterone was licensed by the European Medicines Agency (EMA) in September 2011. After price changes made the drug more affordable, NICE guidance recommended abiraterone for use within certain circumstances. NICE said it is suitable is for men with:

• metastatic prostate cancer that has not responded to castration (either surgical where the testes are removed, or where medical treatments are used to block male hormones); and
• metastatic prostate cancer that has not responded to a chemotherapy regimen that contains docetaxel (a chemotherapy drug licensed for hormone-resistant prostate cancer)

NICE added that abiraterone should be used in combination with the anti-inflammatory drug predisnolone (or prednisone) in both these cases.

Alternative treatment options for men with metastatic prostate cancer, whose disease still progresses after treatment with docetaxel, include a drug called mitoxantrone, supportive care and re-treatment with docetaxel (which is not recommended in current NICE guidance).

 

How effective is it?

NICE has concluded that abiraterone is an effective second-line treatment for advanced (metastatic) prostate cancer.

Evidence for its effectiveness comes from a large randomised controlled trial carried out in 13 countries including the UK, from May 2008 to April 2009. The trial aimed to find out how well abiraterone worked for men who had already had other types of hormone therapy and chemotherapy for advanced prostate cancer.

One group of men in the trial took abiraterone once a day together with prednisolone, while the other group took a placebo plus prednisolone.

A primary analysis of the results showed that, on average, men who had abiraterone survived about four months longer than those in the placebo group (14.8 months compared with 10.9 months, hazard ratio 0.65, 95% confidence interval 0.54 to 0.77). The trial was stopped early once the benefits of the drug became clear.

The study also included analysis of a subgroup that had received one course of chemotherapy only (as opposed to more than one). It found that in this group, men who took abiraterone lived significantly longer than men who took the placebo (17.0 months compared to 11.7 months, hazard ratio 0.71, 95% confidence interval 0.60 to 0.86). NICE said that this group is likely to be treated with abiraterone in clinical practice and would have better treatment outcomes because they had less advanced disease.

Experts also told NICE that the most important benefits were extension to life and improved quality of life, including less pain and improved mental and physical health. NICE also concluded that the drug has the benefit of being in tablet form, which means patients can take it at home. It added that abiraterone is generally safe and any adverse reactions were tolerable.

 

Why was the drug previously turned down by NICE?

NICE had previously said that abiraterone should not be made available on the NHS because it was not cost-effective. NICE uses a measure called the quality-adjusted life year (QALY) to assess the value for money of a medical intervention. QALY is based on the number of years of life that would be added to a patient’s life, as well as the improvement in the quality of their life in that time added by any treatment. Each year of life is assigned a value.

NICE had previously said that although the drug had survival benefits, it did not feel the drug provided enough benefit to patients to justify the price the NHS was being asked to pay, even with an (undisclosed) discount on the list price then offered by the manufacturer, Janssen. It concluded that the most plausible cost per quality adjusted life year would be at least £63,000.

The list price of abiraterone is £2,930 for a 30-day supply of 120 tablets.

It also said that the drug did not meet its criteria for an end-of-life treatment as it did not consider the population for which the drug is licensed to be small.

 

What has changed now?

The manufacturer of abiraterone, Janssen, has offered the NHS a further undisclosed discount on the list price of the drug. Janssen also offered further information on which patients would benefit most (the subgroup who received only one course of chemotherapy), and clarified how many patients would receive the drug as an end-of-life treatment.

This has enabled NICE to conclude that the plausible cost per quality adjusted life year for this subgroup would be less than £50,000. In coming to this revised figure, NICE also took into account that abiraterone has other quality-of-life benefits, such as being an oral drug. It also meets the criteria for an end-of-life treatment which are:

• it would be used for men who would have a short life expectancy without treatment - less than 24 months 
• providing treatment would provide at least three months extension to life.

 

Is it definitely going to be made available?

NICE will now consult with interested parties on the new draft guidance recommending abiraterone, before it makes a final decision in June. Until then, NHS bodies are advised to make decisions locally on the funding of specific treatments.

Links To The Headlines

Prostate drug abiraterone 'set for NHS use'. BBC News, May 16 2012

England benefits from NHS postcode lottery at long last - as prostate cancer wonder drug looks set for approval south of border but not in Scotland. Daily Mail, May 16 2012

Prostate cancer: health watchdog reverses NHS guidance on drug. The Guardian, May 16 2012

Nice 'to reverse ban on prostate cancer drug'. The Daily Telegraph, May 16 2012

NHS ban on pill to treat prostate cancer is lifted. Daily Express, May 16 2012

         

Links To Science

NICE. Prostate cancer (metastatic, castration resistant) - abiraterone (following cytoxic therapy): final appraisal determination guidance. Published May 16 2012

Revolutionary surgery has given a paralysed man the ability to move his arms and hands again, it has been widely reported. The surgery, which made global news, has shown that rewiring nerves may allow surgeons to restore basic arm and hand control after serious spinal cord injuries.

A 71-year-old patient had been left paralysed from the neck down after the base of his neck was injured in a traffic accident. In a world first, surgeons were able to successfully bypass the injury site by grafting arm nerves from below the injury to nerves originating above the site of his injury. The surgery was given 23 months after his accident, and after several more months of therapy and training the man can handle objects, feed himself and even do basic writing.

This success story is clearly of massive significance to the man involved but also provides a blueprint for other surgeons around the country for how this technique may be applied in similar situations. However, despite this fantastic success, it is important to bear in mind that this was an individual case, and it is not clear whether this technique will be equally successful in other patients with different types of spinal injuries or circumstances. The severity and location of the spinal cord injury are likely to be important factors in the success of this type of operation.

 

Where did the story come from?

The research was detailed in a report written by researchers from the Division of Plastic and Reconstructive Surgery and the Department of Neurological Surgery at Washington University School of Medicine in St Louis, Missouri in the US. The case report was published in the peer-reviewed Journal of Neurosurgery. The report did not specify any sources of funding for the research.

This story received widespread media coverage and many papers reported on the restoration of function in a previously paralysed man. The coverage of the story was generally well balanced and reflected the case report accurately.

 

What kind of research was this?

This case report described a surgical technique designed to restore nerve function to the arms and hands of a 71-year-old man who had been injured in a road traffic incident and left paralysed. The patient had experienced severing of the spinal cord at the top of his spine, causing him to be paralysed below the site of his injury. This meant the paralysis affected his arms and hands, as the nerves that control the arms are situated below the site of his spinal cord damage.

In this cutting-edge research surgeons created a 'nerve bypass' by grafting a working nerve originating in the spine above the injury site to the nerves in the lower arm originating below the injury site to restore some level of control lost following the injury.

Spinal cord injury (SCI) is devastating for the individuals affected and their families. Recovery from a complete SCI is rare, leaving most patients with significant permanent disability affecting the area below the site of the SCI. Despite advances in understanding the processes that occur in short- and long-term SCI, corresponding advances in surgical techniques or applications to repair them have so far lagged behind.

Case reports are often published that share interesting developments or new techniques in a particular medical field, in this case surgery. Case reports provide a detailed description of the background of a single person and the treatment they received, along with how effective the particular treatment course has been. They do not necessarily reflect what will be seen in all patients treated with the same techniques in the future, but still provide a good insight into new or experimental techniques.

 

What did the research involve?

The right-handed 71-year-old man presented to a surgical department 22 months after he was injured in a motor vehicle accident. He had sustained a spinal injury to the lower part of his neck, called the C7 vertebra. This caused extensive paralysis below the injury site. The strength and mobility of his limbs were extensively assessed to see if surgery might be able to help. Before surgery, he could flex his right wrist only weakly and could not pinch or grip with either hand. He could also not move his fingers on either hand.

A month after his initial assessment, the patient had surgery on both arms in a bid to restore some of the function of his hands. This was based on the concept that a working nerve originating in the spine above the injury site could be grafted onto the nerves in the lower arm to restore some of the control lost after the injury.  The 'nerve transfer' surgical technique involved taking a working nerve in the upper arm that originates from the C6 vertebral level (above the site of the injury), and joining it to the nerve system in the arm that originates from the C7 vertebra (the site of the injury).

This 'nerve rewiring' allowed working nerves above the spinal injury site to artificially connect with nerves below the injury site, which were previously unable to receive a signal due to the injury. Nerve transfer for spinal injuries is not new, but its application has so far been relatively limited.

After the surgery, the patient received continued hand physiotherapy to aid recovery and rehabilitation of the wasted hand muscles due to the injury.

 

What were the basic results?

During the operation, the surgeons stimulated the newly rewired nerves to check they were working and found that the nerve responses were essentially normal for the rewired nerves feeding the hand.

Eight months after the operation, the patient was able to move his left thumb and perform a pinching motion with his fingers and thumb in his left hand. The same increase in movement was achieved in the right hand after 10 months.

The authors report that he can now use his right hand to perform simple 'hand to mouth movements', and with his left hand he can feed himself and perform rudimentary writing activities. Recovery in the right hand has been slower than in the left.

Videos made available by the study group show that the man is now able to handle a ball with both hands, touch his fingers against his thumb in a pinching motion and feed himself. These were all activities he could not do before the surgery.

 

How did the researchers interpret the results?

The researchers said that, to their knowledge, this is the first reported case of restored nerve control of the thumb and finger flexing movement after a spinal cord injury.

They also said the patient’s 'function has improved significantly with his ability to feed himself'.

 

Conclusion

This case report represents the positive experience of a paralysed 71-year-old man who has been granted some manual control after a serious spinal injury to his neck. Before surgery, he could only make minimal arm movements controlled by the nerves above his injury site, but no lifting or fine hand movements as they are controlled by nerves joined lower down the spine, below the site of his injury.

While the nerve transfer technique given to this patient is not new, its application is not widespread and the authors say this is the first time it has been used to successfully rewire the nerves supplying a hand. Furthermore, these gains occurred after surgery that was carried out 23 months after the injury was sustained. This suggests that surgery does not have to be performed immediately, and that it may be possible to carry out the technique in people who have been paralysed for some time.

In addition to the hugely significant benefits to the man involved, this success story has also created a blueprint for other surgeons around the country for how this technique may be applied in similar cases.

However, it is important to bear in mind the limitations of the surgery and the evidence of its effectiveness. This case report represents the experience of just one individual. Therefore, it is not clear whether this technique will be equally successful in other patients with different types of injuries or circumstances. The severity and location of the spinal cord injury are likely to be important in determining the relative success of this type of operation. Also, the level of strength and control achieved in this case did not appear to represent a complete restoration of arm function, although it was clearly still a massive improvement.

Analysis by Bazian. Edited by NHS Choices.

Links To The Headlines

Prostate drug abiraterone 'set for NHS use'. BBC News, May 16 2012

For once England benefits from NHS divide as Nice set to approve prostate cancer drug turned down by Scotland. Daily Express, May 16 2012

Prostate cancer: health watchdog reverses NHS guidance on drug. The Guardian, May 16 2012

Prostate drug u-turn by NICE. The Daily Telegraph, May 16 2012

Nice 'to reverse ban on prostate cancer drug'. The Daily Telegraph, May 16 2012

NHS ban on pill to treat prostate cancer is lifted. Daily Express, May 16 2012

Links To Science

Mackinnon SE, Yee A, Ray WZ. Nerve transfers for the restoration of hand function after spinal cord injury. Journal of Neurosurgery, Published online May 15 2012.

New research has mapped the way that MRSA “superbug” bacteria spread, BBC News has reported. The results suggest that antibiotic-resistant bacteria may often spread from large, inner-city hospitals to smaller regional ones when patients are transferred.

The way that superbugs spread has been researched as part of an intricate study conducted by Scottish researchers, who looked at samples taken across the UK over 53 years. The researchers used genetic techniques to scan patterns and mutations within the various samples and to build up a “family tree” showing how a particular strain (called EMRSA-16) has spread between different hospitals across the country. They found that EMRSA-16 has generally spread by transmission from hospitals in large population centres in London and Glasgow to regional healthcare settings. The researchers suggested that patients’ referrals are an important cause of the spread of this bug across the country.

This type of study can provide useful estimates of transmission routes of MRSA, although there is still a need for further research incorporating a larger number of sampled hospitals to determine the wider UK pattern.

MRSA can be prevented through effective hand washing and screening before hospital admission. Find out more about preventing MRSA.

 

Where did the story come from?

The study was carried out by researchers from the University of Edinburgh and was funded by various research grants, as well as US governmental organisations including the National Institute of Allergy and Infectious Diseases, the National Institutes of Health and the Department of Health and Human Services. The study was published in the peer-reviewed journal Proceedings of the National Academy of Sciences USA (PNAS).

The story was covered accurately by BBC News.

 

What kind of research was this?

This study used genetic analysis of bacteria samples to map the way a particular form of MRSA spread between patients and hospitals across the UK. It collected information from infected patients in the UK over 53 years and looked at the emergence and transmission of EMRSA-16, a major clone (type) of MRSA. The study identified genetic elements and mutations of EMRSA-16 that allowed it to spread between patients and hospitals across the county.

MRSA (meticillin-resistant staphylococcus aureus) is a type of bacterial infection that is resistant to a number of widely used antibiotics. It is often referred to as a “superbug”. MRSA infections are more common in hospitals because patients often have an entry point, such as a surgical site, which allows the bacteria to enter the body. Also, bacteria can easily spread through direct contact with other patients and staff or contaminated surfaces.

Proper hand washing and screening are effective methods used to prevent MRSA infections from occurring. Rates of MRSA have fallen in recent years because of increased awareness of infection by both medical staff and the general public. However, it still places a considerable strain on the health system as it is more difficult to treat than other types of bacterial infection. Currently, all patients who go to hospital for a planned procedure are offered a swab test to see whether they are carrying MRSA bacteria.

 

What did the research involve?

Researchers looked at the genetic make-up of more than 80 variations of a major clone of MRSA called EMRSA-16 found in hospitals. Samples were collected from infected patients during a 53-year period. The EMRSA-16 clone of MRSA predominantly occurs in hospitals, and the researchers estimated that it has been present in UK hospitals for about 35 years. Researchers then identified genetic elements and mutations in the bug and tracked how these spread between patients and hospitals across the country.

Researchers used a specialist approach to map part of the genetic make-up of each sample, looking for changes and patterns in its genetics. In effect, this allowed them to build up a “family tree” showing how different strains had developed.

 

What were the basic results?

The key finding of this study was that EMRSA-16 has spread within the UK by transmission from central hospitals serving large populations to smaller, regional healthcare settings. It found that Glasgow in west Scotland was a hub for transmission to 16 surrounding regions in the north and east of Scotland. Similarly, in London EMRSA-16 spread from large city hospitals to smaller surrounding hospitals in south and southeast England.

 

How did the researchers interpret the results?

Study lead Dr Ross Fitzgerald reported that “our findings suggest the referral of patients to different hospitals is a major cause of MRSA transmission around the country.” He also said that “variants of MRSA circulating in regional hospitals probably originated in large city hospitals.”

The researchers concluded that these findings could help prevent the spread of drug-resistant infections such as MRSA.

 

Conclusion

This study estimates how a strain of MRSA (EMRSA-16) may spread from hospitals in major UK cities to smaller regional healthcare settings. Findings from this study are supported by findings of a recent US study, which estimated high transmission routes from large hospitals to long-term care facilities.

The researchers note that the dataset used is limited by the relatively small number of hospitals sampled. Despite its interesting findings, further research is required that incorporates a larger number of sampled hospitals to determine the pattern of spread elsewhere in the UK.

Collecting data on the prevalence and spread of superbugs such as MRSA (medically known as surveillance) plays an important role in containing and eradicating potentially harmful bacteria in medical settings, and ultimately reducing the number and severity of hospital-acquired infections. When used strategically, data of this type, along with simple but effective measures such as thorough hand washing, can make a difference to the spread of infections, as illustrated by the recent fall in MRSA in NHS hospitals.

Analysis by Bazian

Links To The Headlines

Large city hospitals 'breed and spread' MRSA. BBC News, May 15 2012

MRSA outbreaks start at major city hospitals. Daily Express, May 15 2012

Links To Science

McAdam PR, Templeton KE, Edwards GF et al. Molecular tracing of the emergence, adaptation, and transmission of hospital-associated methicillin-resistant Staphylococcus aureus. PNAS, Published online before print May 14 2012

“Overweight mothers-to-be could be condemning their unborn children to decades of ill health,” the Daily Mail reported.

The news is based on the results of large, long-term research that examined mothers’ body mass index (BMI) before and during pregnancy and how this was linked to various indicators of their children’s health when their children reached 32 years of age. These indicators included BMI, waist size and levels of fat and sugar in the blood, which are associated with the risk of conditions such as diabetes and heart disease.

Researchers found that higher maternal BMI before pregnancy was associated with increased BMI in children, as well as larger waistlines, raised blood pressure and increased blood levels of insulin and fat. Greater maternal weight gain during pregnancy was also associated with increased BMI, waist size and levels of fat in the blood.

This study adds to a growing body of evidence that mothers’ weight before and during pregnancy may affect a range of health-related factors in their children, perhaps even in the long-term. That said, this study’s design means that on its own it cannot prove that a mother’s weight or weight gain during pregnancy are responsible for the health effects seen in their grown-up children. For example, many complex environmental, social and genetic influences are known to determine who develops obesity.

Although the long-term effects of maternal weight are unclear from this study, excess weight is known to increase the risk of complications during birth, as well as making it harder to conceive in the first place. This study highlights the importance of maintaining a healthy weight for these reasons, rather than the potential long-term ones.

The Daily Mail also reported that “concern about the issue is so high that British doctors have started to medicate babies in the womb.” The newspaper appears to be referring to ongoing research into treating women for high blood sugar during pregnancy. This valuable study primarily aims to treat mothers, rather than their unborn babies, to cut potentially dangerous complications, rather than to improve their children’s long-term health.

 

Where did the story come from?

The study was carried out by researchers from the Hebrew University-Hadassah in Israel and the University of Washington in the US. It was funded by the US National Institutes of Health and the Israeli Science Foundation. The study was published in the peer-reviewed medical journal Circulation.

The story was accurately covered by the Daily Mail. However, it should be noted that this study measured factors that can contribute to various diseases, but did not determine the rates of negative health outcomes such as heart attacks, diabetes and strokes mentioned in the news coverage.

 

What kind of research was this?

This cohort study examined how mothers’ BMI and weight changes during pregnancy were associated with various markers of disease in their children once they reached adulthood. The disease markers of interest were waist circumference, BMI, blood pressure and levels of glucose, insulin, fats and lipoproteins in the blood. These were measured once the children reached 32 years of age. Maternal BMI and weight changes during pregnancy were reported by mothers in interviews conducted by nurses while they were in hospital after having their baby.

This is the ideal study design to examine a possible association between maternal weight and children’s health. The study’s strengths also included its large size and long follow-up. However, this type of study can only find associations between factors, and cannot prove a cause-and-effect link. This is because researchers cannot exclude the possibility that another factor is responsible for the association seen.

 

What did the research involve?

This research drew on data from a large, long-running study called the Jerusalem Perinatal Study. The research collected the following information on births in Jerusalem between 1974 and 1976:

• demographic and socioeconomic information
• medical conditions of the mother during current and previous pregnancies and gynaecological history
• smoking status of the mother
• height, pre-pregnancy weight and end-of-pregnancy weight of the mother
• child’s birth weight and gestational age

This information was obtained from maternity ward logbooks, birth certificates and interviews with mothers while they were hospitalised after having their baby.

In this study, a sample of 1,400 individuals born during this period was interviewed and examined again between 2007 and 2009 (when they reached 32 years of age). Individuals who had been born as part of a multiple birth, who were premature or who had congenital malformations were excluded. The researchers collected data on:

• height
• body weight
• waist circumference
• blood pressure
• levels of glucose, insulin and fats in the blood

The researchers looked at associations between maternal pre-pregnancy BMI and weight gain during pregnancy and children’s outcomes at 32 years of age. During their calculations, they accounted for gender, ethnicity and other factors that could explain any relationship seen, including:

• how many previous pregnancies a mother had had
• the mother’s age at the birth
• maternal smoking, and smoking status of the children as adults
• socioeconomic status
• maternal education, and education of the children
• maternal medical condition
• the children’s birth weight and gestational age
• physical activity of the children 

 

What were the basic results?

The researchers found that greater maternal BMI before pregnancy was associated with the following factors in grown-up children at the age of 32:

• increased BMI
• increased waist circumference
• increased blood pressure
• increased blood levels of insulin and fat 
• lower levels of high-density lipoprotein cholesterol

These associations were independent of weight gain during pregnancy (i.e. were evident regardless of how much weight a mother gained during pregnancy).

Greater weight gain during pregnancy was associated with:

• increased BMI
• increased waist circumference
• increased blood levels of fat 

When calculating these various associations, the researchers split mothers into four evenly sized groups, based on their pre-pregnancy BMI. They found that, on average, the adult children of women in the group with the greatest BMI (maternal BMI more than 26.4kg/m2) went on to have a BMI of  five units (kg/m2) higher than the children of mothers in the lowest quarter (maternal BMI less than 21.0kg/m2).

 

How did the researchers interpret the results?

The researchers concluded that “maternal size both before and during pregnancy is associated with cardiometabolic risk factors in young adult offspring.”  In other words, mothers who have a high BMI before pregnancy or who gain a lot of weight during pregnancy are more likely to have children who have risk factors for various metabolic and heart-related health problems in adulthood.

The researchers added that these associations appear to be driven mainly by children’s body fat during adulthood.

 

Conclusion

The link between pregnant women’s weight and the health of their children has been in the public eye several times in recent months, with high-profile news stories questioning whether our mothers can “programme us to be fat” and the need to “treat babies for obesity while still in the womb”.

This latest study analysed potential links between mothers’ excess weight around the time of pregnancy and “cardiometabolic risk factors” in their children decades later. Cardiometabolic risk factors are factors such as raised BMI and blood sugar, which signal that a person has a higher risk of conditions such as diabetes and heart disease.

The study found a long-term relationship, with higher maternal weight (assessed using BMI) and greater weight gain during pregnancy associated with a number of factors in the mothers' children at the age of 32. These included increased BMI, waist circumference, blood pressure and blood levels of insulin and fats, and decreased levels of high-density lipoproteins (“good cholesterol”) in children. As the authors state, this study “adds to and extends accumulating evidence” of this relationship, as similar findings have been reported in other studies.

This study has shown associations between maternal weight and children’s later health, but it cannot show cause and effect. This is because it cannot rule out the possibility that another factor is responsible for the association seen. Also, both pre-pregnancy weight and weight gain were not directly measured but were reported by mothers in interviews conducted by nurses after delivery. This may have led to some inaccuracy in the calculation of BMI and makes the results less reliable.

The average pre-pregnancy BMI of women in this study was 24kg/m2 (within the healthy range) in mid-1970s Jerusalem. This population may not be typical of pregnant women in the UK today.

In addition, the exact mechanism by which maternal pre-pregnancy weight and weight gain during pregnancy might cause increased levels of cardiometabolic risk factors in children remains to be determined. Several mechanisms, including shared genetic and environmental characteristics or changes caused by exposures in the womb, have been proposed, although none is completely clear.

Analysis by Bazian

Links To The Headlines

Obesity legacy of mums-to-be: Carrying too many pounds in pregnancy can give your baby a life of weight problems. Daily Mail, May 15 2012

Links To Science

Hochner H, Friedlander Y, Calderon-Margalit R et al. Associations of maternal prepregnancy body mass index and gestational weight gain with adult offspring cardiometabolic risk factors/clinical perspective : The Jerusalem perinatal family follow-up study. Circulation, February 17 2012, 2012;125:1381-1389 (published online before print)

Women concerned about PIP breast implants can find all the latest NHS information about the issue in our Health A-Z section on PIP implants.

Worries about the implants have emerged since news of a major investigation into them in France was widely covered in the media in December 2011.

Initially it was thought that around 40,000 women in the UK had the implants but on March 15 the Department of Health said new evidence meant a further 7,000 women in the UK might have them. About 95% of the implants were provided privately for purely cosmetic reasons.

The French implants caused global concern after it was revealed they contained industrial silicone rather than medical-grade fillers and that they may be more prone to rupture and leakage than other implants.

Initially reports also linked the implants to a rare form of cancer known as ALCL. This cancer link has been now been firmly discounted by medical experts here and in Europe.

 

What type of implants are involved?

The implants involved are called Poly Implant Prosthèse (PIP) and were made by a French company of the same name.

In a Medical Device Alert in March 2010, the Medical and Healthcare products Regulatory Agency (MHRA) said: " ... most
breast implants manufactured by the company since 2001 have been filled with a silicone gel with a composition different from that approved".

That alert was based on advice from French regulators. However, after an investigation by the MHRA, the French authorities reported in March 2012 that PIP implants made before 2001 may also contain unauthorised silicone gel.

PIP gained approval to market its silicone implants in 1997 but it is not clear when it began using a cheap type of silicone gel intended for making mattresses.

The marketing, distribution and use of the PIP implants was suspended in March 2010.

 

Do the implants have to be removed early?

About one breast implant in five needs replacing within 10 years, whatever the make, so it is unlikely that all the 7,000 women who had PIP implants before 2001 still have the same implants.

An expert committee was set up recently to examine the specific risks associated with PIP implants. It concluded that there was not enough evidence to recommend their early removal. That advice has not changed. For more details, read the expert review group's report (PDF, 159kb).

Links To The Headlines

No Routine Removal For PIP Breast Implants. Sky News, January 6 2012

NHS will remove implants free of charge for their patients but private clinics must pay for operations themselves, Government says. Daily Mail, January 6 2012

Government will pay for women who had breast implants on NHS to have them removed. The Daily Telegraph, January 6 2012

Clinics 'should remove implants'. BBC News, January 6 2012

The NHS “spends £1m a week on repeat abortions”, the Daily Mail reported. The newspaper claimed that single women are using terminations “as another form of contraceptive”, and that some will have “seven, eight or even as many as nine terminations in their lifetime”.

The Mail’s coverage seems to be a response to a request for data on repeat abortions that was made in parliament in April 2012. The article appears to draw on 2010 abortion statistics available from a Department of Health report. The annual report provides data on the number of abortions (medically termed “termination of pregnancy”) performed in the UK, and includes a section on repeat abortions.

Despite the Daily Mail's headline, the report does not provide any data or information on women’s reasons or motivations for seeking an abortion. The “abortion as contraception” claim appears to be an interpretation of the data provided by campaign groups and abortion legislation critics. Also, the data suggest that only a tiny fraction of abortions were in women who have had seven or more previous abortions – 85 procedures out of the 189,574 performed in 2010.

 

What is a repeat abortion?

Much as the term implies, a repeat abortion is an abortion in a woman who has had one or more previous abortions. The Department of Health has recorded the rate of repeat abortions for many years, and includes a section on repeat abortions in its annual report on abortion statistics.

 

How many repeat abortions are happening each year?

According to the Department of Health’s abortion statistics report, in 2010 there were 189,574 abortions in England and Wales (data are available on residents of England and Wales only). Approximately 64,445 (34%) of these were repeat abortions. The percentage of repeat abortions was found to increase with age: 8% of those under 18 years old had a repeat abortion compared with 44% of women over the age of 35. While it may initially seem puzzling why older women have more repeat abortions, a logical, cumulative effect of ageing is responsible. Put simply, the longer a woman has been alive, the greater time she has had to undergo a repeat abortion.

The Department of Health report also provides data on the percentage of abortions that are repeat abortions in women aged under 25. In 2010 in England and Wales, this figure was 24.8%, with the figure varying across difference primary care trusts (range 15% to 41%).

The Department of Health reports that “repeat unintended pregnancy and subsequent abortion is a complex issue associated with increased age”, as increasing age allows for a longer time at risk for becoming pregnant.

 

Are repeat abortions increasing?

Full sets of annual data have so far been published up to 2010, with figures for 2011 scheduled for publication in the near future. Between 2000 and 2010, there was a small rise in the number of total abortions, up from 175,542 to 189,574. The 2010 figure was, however, slightly lower than the peak number seen in 2007, when there were 198,499 abortions.

The Department of Health data also indicate that the proportion of all abortions that are considered repeat abortions has increased from 30% to 34% since 2000. In absolute terms, this was estimated to equate to 52,663 repeat abortions in 2000 and 64,445 in 2010.

 

Why have these figures come to light now?

It is not immediately clear from the Mail’s coverage why these figures are making headlines today. On April 16 2012, the Labour MP Diane Abbot asked the secretary of state for health to provide estimates on the number of repeat abortions performed in 2010, 2011 and 2012. She asked that these figures be provided based on the marital status and age of the women across each primary care trust.

However, as abortion figures are published a year in arrears, the 2012 figures will not be published until 2013. Also, the 2011 figures are not scheduled for official publication until the end of May 2012, meaning that only figures up to 2010 are available at this time. The House of Commons website also reports that the 2010 statistics provide information on the number of repeat abortions by age, but not marital status. The Daily Mail, however, quoted statistics based on both age and marital status, and it is unclear how these have been derived.

 

Is abortion used as a 'form of contraception'?

In the UK, abortion is legal if one of several conditions apply:

• continuing the pregnancy would involve risk to the life of the woman
• termination of the pregnancy is required to prevent serious permanent injury to the woman
• the pregnancy has not gone beyond 24 weeks, and continuing would involve risk to the physical or mental health of the woman, greater than if the pregnancy was terminated
• the pregnancy has not gone beyond 24 weeks, and continuing would involve risk to the physical or mental health of any existing children, greater than if the pregnancy was terminated
• there is a significant risk that the child would suffer physical or mental abnormalities leading to serious handicap
• emergency situations to save the life of the woman
• emergency situations to prevent serious permanent injury to the woman

The Department of Health report on abortion statistics provides information on which of these conditions applies to each registered abortion. It does not, however, provide any specific data on the reasons why women decided to seek an abortion. The idea that abortion is used “as contraception”, as reported in the Daily Mail, appears to be an interpretation of the abortion statistics data by critics of the current legislation, with the newspaper quoting pro-life campaign groups and critics of current abortion legislation.

 

Who can give advice about reproductive health and contraception?

People seeking advice on reproductive health and contraception can speak with their GP or a community family planning clinic. GUM (genitourinary medicine) clinics, which are often located in hospitals, can also provide contraceptive services and sexual health advice. For younger adults in particular, voluntary organisations such as Brook advisory centres also provide a wide range of sexual health services.

Links To The Headlines

NHS spends £1m a week on repeat abortions: Single women using terminations 'as another form of contraceptive'. Daily mail, May 14 2012

NHS 'spends £1m on repeat abortions'. The Daily Telegraph, May 14 2012

Repeat abortions cost NHS £50m a year. Daily Express, May 14 2012

Cholesterol-lowering statin drugs “could more than halve the risk of bowel cancer”, according to the Daily Mail.

Millions of people take statins in a bid to prevent problems such as heart attacks and strokes, but several recent studies have looked at whether they might also cut the risk of cancer. This latest news is based on a study of statin use in people with and without bowel cancer. It looked at use of the drug in a group of 101 bowel cancer patients and 132 people without cancer. It found that statin users had a lower risk of developing bowel cancer, and that higher doses and longer duration of statin use were associated with a greater reduction in the odds of having the disease.

Previous research into the potential effect of statins on bowel cancer has had mixed results. Some studies have suggested that the drugs have a protective effect, and others have found no clear association between statin use and bowel cancer risk. It is important to note that this latest study is small, so its results may be inaccurate. This means the results need to be replicated in much larger samples of people. Also, all patients in this study – with or without cancer – were included because they were undergoing colon examinations for bowel symptoms, so they may not represent the general population.

Nevertheless, this small study adds to the mounting evidence that stains may have an effect in protecting against the development of certain cancers. However, more research is needed to confirm the findings and establish how large this protective effect may be.

 

Where did the story come from?

The study was carried out by researchers from the University of East Anglia and the Norfolk and Norwich University Hospital. It was funded by the Norwich Medical School.
 
The study was published in the peer-reviewed journal Biomed Central Gastroenterology.

This research was covered appropriately by the media, with the Daily Mail reporting that previous studies have found conflicting results and that additional research is needed. The newspaper also reported the possible side effects of statin use.

 

What kind of research was this?

This case-control study examined the association between statin use and bowel cancer. Case-control studies are a useful way of examining some types of association. They recruit and compare two groups of participants who either have or don’t have a particular disease or condition. For example, this study compared the histories of people with bowel cancer to those of similar participants without the condition. This allows researchers to study a relationship without having to recruit a large number of participants and follow them up over a long period.

Case-control studies have weaknesses, however, including relying on participants to accurately recall their past behaviour and exposures, often over many years. This can introduce bias into the results as such recollection can be difficult, particularly if someone is trying to understand why they have developed a condition such as cancer. Overall, the limitations of case-control studies mean they are considered to show only associations between two factors, and not that one factor causes the other.

Arguably, as both statin use and bowel cancer are fairly common among the general population, it would be possible to conduct a cohort study to examine bowel cancer development in a large sample of statin users and non-users. A study of this type would take a large group of participants using statins and follow them over time to see which of them developed cancer. It would then examine differences between the participants that may have contributed to the development of cancer. Alternatively, a carefully controlled randomised controlled trial would be the best way to examine this question, although it would need to be carried out over a long period as bowel cancer can take many years to develop.

As mentioned above, case-control studies cannot prove that a particular exposure (such as statin use) causes a particular outcome (such as a reduction in bowel cancer). They are, however, still a useful way to explore potential relationships, and are often conducted as a way to justify attempting large cohort studies or randomised controlled trials. In short, they provide useful initial data that will need to be corroborated through more intensive types of research.

 

What did the research involve?

The research included people who had undergone a colonoscopy at the Norfolk and Norwich University Hospital between September 2009 and May 2010. All the participants had bowel symptoms which led them to be referred to the hospital for a diagnostic colonoscopy examination. A colonoscopy involves inserting a long, flexible camera into the bowel to look for abnormalities such as tumours, pre-cancerous cells or damage. The study excluded patients who received a colonoscopy for surveillance of current or previous illnesses (such as inflammatory bowel disease), and symptomless patients who received a precautionary screening colonoscopy because they were considered to be at higher risk of bowel cancer (for example, those with a strong family history of bowel cancer).

Bowel cancer cases were identified based on a positive result during a diagnostic colonoscopy test, and control subjects were drawn from patients who had a negative test result. All the participants completed an interview during which information on statin use was collected. The researchers also collected information on other known risk factors for bowel cancer, which were adjusted for during the statistical analysis.

The researchers compared the percentages of cases and controls who reported taking statins, and determined whether the odds of having bowel cancer changed depending on statin use. They performed further analysis to determine whether or not the dose, duration or type of statin used was associated with differing risk of developing bowel cancer. All analyses were presented as odds ratios (OR). This is an appropriate statistical method to use in case-control studies. Odds ratios compare the odds of an outcome in an exposed group (statin users) with the odds of the same outcome in an unexposed group (non-users).

 

What were the basic results?

The research included 101 patients with bowel cancer and 132 cancer-free controls. There were some differences between the two groups. Cases were more likely to be male, older and to drink more alcohol during the course of a week. Controls were more likely to have diabetes and to have previously used aspirin (some research has linked long-term aspirin use to a reduced risk of bowel cancer). These factors were considered to be potential confounders and were controlled for in the statistical analysis.

The researchers found that previous statin use for at least six months was associated with significantly reduced odds of being diagnosed with bowel cancer (OR 0.43, 95% confidence interval [CI] 0.25 to 0.80).

When the researchers performed subgroup analysis based on the duration of statin use, they found that longer statin use was associated with a greater protective effect:

• 8 cases and 14 controls had used statins for less than 2 years. There was no significant difference in the odds of a bowel cancer diagnosis between statin users and non-users (OR 0.66, 95% CI 0.21 to 1.69).
• 7 cases and 23 controls had used statins for 2 to 5 years. There was no significant reduction in odds of bowel cancer diagnosis (OR 0.38, 95% CI 0.14 to 1.01).
• 5 cases and 31 controls had used statins for over 5 years. This was associated with an 82% reduction in the odds of being diagnosed with the disease (OR 0.18, 95% CI 0.06 to 0.55). This particular association was statistically significant.

When the researchers performed subgroup analysis based on the statin dose, they found larger doses were associated with a greater protective effect:

• 12 cases and 28 controls used a dose of less than 40mg a day. There was no significant reduction in odds of bowel cancer diagnosis at this dose (OR 0.51, 95% CI 0.21 to 1.24).
• 8 cases and 40 controls used a dose of 40mg or greater a day. This was associated with an 81% reduction in the odds of being diagnosed with the disease (OR 0.19, 95% CI 0.07 to 0.47).

 

How did the researchers interpret the results?

The researchers concluded that statin use was associated with a reduction in bowel cancer diagnosis, and that this reduction was largest at higher doses and with longer duration of statin use.

 

Conclusion

This study suggests that stains, a commonly prescribed class of cholesterol-lowering drugs, may protect against bowel cancer. However, further research with more participants and a more robust study design will be needed to confirm its findings.

This was a relatively small study, which was further divided during subgroup analysis. Analysing small numbers of participants increases the possibility that any risk associations calculated could be inaccurate. Larger studies are needed to verify the associations found in this research.

The researchers report that one of their study’s strengths is that a comprehensive drug history was available, both through prescription records and patient reports. This increases the likelihood that exposure to statins was correctly classified. Additionally, all the participants underwent the same diagnostic testing to confirm or rule out the presence of bowel cancer.

There were, however, limitations to the study. For instance, all the participants had symptoms that indicated the need for a colonoscopy. Given that the control group may have had health issues relating to their bowels, the results may not reflect the risk of bowel cancer in the wider population. Further studies including participants receiving a screening, rather than diagnostic, colonoscopy could help address this potential bias.

When being used to treat or prevent cardiovascular problems, statin drugs may be given as part of a package of treatments including dietary changes and salt reduction. It’s possible that people with the greatest need for cholesterol-lowering statins may also modify their diet alongside their use of statins. Given that diet is associated with bowel cancer risk, dietary changes (and not just the use of statins) may have played a role in the association. This study did not investigate the participants’ dietary habits. Future studies could examine this risk factor.

The researchers say that the protective effect seen in their study was greater than that seen in other studies with similar results. They also point out that not all previous research has found a protective effect, and that there are inconsistent findings across the field. They say that these inconsistencies may be due to differences in the populations studied, or the duration of statin use. Given the variability in results, more research is needed before we can be confident that statins are indeed associated with a reduced risk of developing bowel cancer. Ideally, this research should be a prospective cohort study or randomised controlled trial.

Overall, this case-control study adds to the existing evidence that statin use has a potential protective effect against the development of bowel cancer. Further research is needed to confirm the findings, and the risks associated with statin use will need to be weighed up against any benefits before the drugs are considered for cancer-prevention.

Analysis by Bazian

Links To The Headlines

Statins 'cut risk of bowel cancer': Danger 'halved' by cholesterol-busting pills. Daily Mail 11, May 2012

Links To Science

Broughton T, Sington J, Beales ILP. Statin use is associated with a reduced incidence of colorectal cancer: a colonoscopy-controlled case-control study. BMC Gastroenterology. April 24 2012

“Women using a vaginal ring or skin patch for contraception are at around double the risk of a blood clot compared to those taking the Pill,” the Daily Mail has reported.

The news is based on a large Danish study that looked at contraceptive use in more than 1.5 million women. The study looked at how different hormone-based methods such as implants, the patch and the pill related to the risk of blood clots. Between 2001 and 2010 researchers recorded a total of 3,434 blood clots, also known as venous thromboembolisms or VTE. The background rate of VTE among women not using hormonal contraception was 2.1 per 10,000 woman-years (for example, 2.1 would occur if 1,000 women were followed for 10 years). The highest rate of VTE was among women who used the contraceptive patch, with 9.7 per 10,000 woman-years. Women using a common oral contraceptive pill experienced a rate of 6.2 per 10,000 woman-years.

Despite what some news coverage might suggest, hormonal contraceptives containing oestrogen ( the combined oral contraceptive pill, transdermal patch and the vaginal ring) are already recognised as increasing the risk of VTE, although the risk is very low. Instead of discovering a new danger from using hormone-based contraceptives, the research simply refines estimates of the clot risk associated with different methods.

Women should be fully informed of the potential risks and benefits of any contraceptive option that they choose. They can talk to their GP or nurse about these. Despite the small increase in risk associated with the patch or vaginal ring compared with the combined oral contraceptive pill, there may be women for whom this is still an appropriate choice.

 

Where did the story come from?

The study was carried out by researchers from the University of Copenhagen and did not receive external funding. It was published in the peer-reviewed British Medical Journal.

News coverage generally failed to reflect the true context of this research. It is already known that there is a clot risk associated with use of oestrogen-containing contraceptives, and this research has helped to analyse some of the finer points around the issue rather than revealing any previously unknown risk. This research provides valuable quantification of the possible risk among users of hormonal contraception but the findings are not as unexpected as the media implies.

In particular, the Daily Mail’s headline is misleading and may scare women: ‘Women using alternative contraception to the Pill are at double the risk of blood clot’. This might suggest to readers that any alternative option to the combined oral contraceptive pill doubles the risk. This is not true. The oestrogen-containing patch or vaginal ring increase risk slightly more than the oestrogen-containing pill, but the pill itself actually significantly increases risk of VTE compared with non-use, or use of progestogen-only contraceptives or barrier methods.

 

What kind of research was this?

This was a large, national cohort study that compared contraceptive use and VTE risk among more than 1 million Danish women. It used four national registries in Denmark to look at all non-pregnant women aged 15-49 (who were free of cancer or thrombotic disease) and collected data on their contraceptive use over the period 2001 to 2010. From these data, researchers were able to see how the rate of VTE among users of non-oral hormonal contraceptives compared with the rate in users of the oral contraceptive pill, as well as in women who didn’t use hormonal contraception.

A cohort study is a good way of evaluating whether a certain exposure increases risk of a certain outcome. The researchers of this cohort study when conducting their analyses have attempted to adjust for some of the possible confounding factors that could be affecting the results.

 

What did the research involve?

Data available in Danish registries allowed for 1,626,158 non-pregnant women to be followed between January 2001 and December 2010. The researchers were only interested in first-ever events of VTE, so excluded women who had had any type of thrombotic event in their veins or arteries before the study period (assessed by checking medical registries from 1977 to 2000). They also excluded those with cancer, those who had had a hysterectomy or both their ovaries removed and those who had been sterilised.

Since 1995 the registries consulted by the study have recorded all filled prescriptions, and so the researchers were able to obtain information on all hormonal contraceptives prescribed between 1995 and 2010. They recorded the products according to progestogen type, oestrogen dose, method of administration and duration of use. The registry also records all hospital admissions.

Any hospital admission for suspected VTE (a clot in a vein or blood vessel) or pulmonary embolus (a clot in the blood supply to the lungs) was confirmed by examining prescribed anticoagulation therapy recorded in the national registry of medicinal products for at least four weeks after the diagnosis. Fatal VTEs were captured by the national causes of death registry.

The researchers also obtained information on some possible confounders that could influence VTE risk, such as educational status, age and calendar year (contraceptives prescribed or healthcare in general may have changed subtly over the nine-year study period). However, they didn’t have information on other relevant confounders such as smoking.

 

What were the basic results?

The researchers had 9,429,128 woman-years of follow-up data (for example, 90 woman-years of follow-up could be 90 women followed for one year, or nine women followed for 10 years). Over this period there were 3,434 confirmed first-event VTEs.

The researchers then calculated the VTE rate according to use of different contraceptive types:

• not using hormone-based contraception: women not using any hormone-based contraception experienced a background rate of 2.1 events per 10,000 woman years (for example 2.1 would occur if 1,000 women were followed for 10 years)
• contraceptive patch: a rate of 9.7 per 10,000 woman years
• vaginal ring: a rate of 7.8 per 10,000 woman years
• combined oral contraceptive pill (30-40 micrograms of oestrogen in combination with levonorgestrel): a rate of 6.2 per 10,000 woman years
• combined oral contraceptive pill (30-40 micrograms of oestrogen in combination with norgestimate): a rate of 4.5 per 10,000 woman years
• progestogen implant: a rate of 1.7 per 10,000 woman years
• progestogen-releasing intrauterine system: a rate of 1.4 per 10,000 woman years

The researchers calculated that, after adjustment for confounders, the risk of confirmed VTE among users of the contraceptive patches was 7.9 times that of women not using hormonal contraception (95% confidence interval 3.54 to 17.65), and 2.3 times that of users of the combined oral contraceptive pill (95% CI 1.02 to 5.23).

The risk of confirmed VTE among users of the vaginal ring was 6.5 times that of non-users, and 1.9 times that of users of the combined oral contraceptive pill. Compared with women who did not use hormonal contraception, women who used the combined oral contraceptive pill had around a trebled risk of VTE.

Compared with women who did not use hormonal contraception, users of the progestogen implant or progestogen-releasing intrauterine system had no increased risk of VTE.

 

How did the researchers interpret the results?

The researchers conclude that “women who use transdermal patches or vaginal rings for contraception have [respectively] a 7.9 and 6.5 times increased risk of confirmed venous thrombosis compared with non-users of hormonal contraception of the same age”. Respectively, this equates to 9.7 and 7.8 events per 10,000 woman-years (for example, for the transdermal patch a rate of 9.7 events among 1,000 women followed for 10 years).

 

Conclusion

This large study provides valuable information on the rate of VTE that may be experienced among users of hormonal contraception.

However, the findings are not completely surprising. Oestrogen-containing hormonal contraceptives are already known to increase the risk of VTE, and medical professionals already consider this potential side effect when prescribing contraception and monitoring patients. Instead of revealing some new or major danger, this study provides a good indication of how the risks compare for a variety of different contraceptive methods.

The oestrogen-containing contraceptives currently available are the combined oral contraceptive pill, the transdermal patch (of which there is one licensed product – brand name Evra) and the vaginal ring (of which there is one licensed product – brand name NuvaRing). There are many different preparations of combined oral contraceptive pill that contain different strengths and forms of oestrogen and progestogen. Different progestogens contained in combined oral contraceptive pills are considered to have a differing effect on risk of venous thromboembolism. This study chose to look separately at VTE rate among users of combined oral contraceptive pills containing levonorgestrel or norgestimate, but there are various other types of progestogen contained in other combined pills, and this study has not examined those.

Progestogen-only contraceptives are not known to increase risk of VTE, and this study supports this. Users of implants and the progestogen-releasing intrauterine system had no higher risk than non-users of hormonal contraception. Information was not available for progestogen-only pills or injections.

There are some further points to note about the study:

• This was a cohort study looking at associations within a large population using contraception in an everyday setting rather than in the artificially controlled setting of a clinical trial. As such, the method of contraception used will have been down to the woman’s personal choice in consultation with her doctor, and there may be health and lifestyle factors that have influenced the choice of contraceptive and that could also influence risk of VTE. The researchers adjusted their results for possible confounders of age, education and calendar year, and also excluded women who may be at particularly increased risk of VTE. However, information on other relevant confounders such as smoking or body mass index was not available.
• Use of contraception was determined by looking at filled prescriptions. Although the women are likely to have used the method prescribed for them, and for the prescribed time period, this may not always have been the case.
• There were far fewer women in the study using the patch (6,178 woman years) or vaginal ring (50,334 woman years) compared with the combined oral contraceptive pill (530,241 woman years). The event rate of VTE among users of the patch or vaginal ring was correspondingly low (six events among users of the patch; 39 with the ring). Therefore, although the ring and patch were calculated to give double the risk of the combined oral contraceptive pill, the low event rates mean that the risk figures are only estimates, and may not be completely accurate. This is reflected by the wide confidence intervals. In other words, even a small spike in cases could inflate the rate seen.

Overall, the study highlights the importance of women being fully informed of the potential risks and benefits of any contraceptive option that they choose. Despite the small increase in risk associated with the patch or vaginal ring compared with the combined oral contraceptive pill, there may be women for whom this is still an appropriate choice and for whom the benefits, such as not having to take a daily pill, outweigh the small extra risk.

Analysis by Bazian

Links To The Headlines

Skin patch contraceptive linked to high blood clot risk: research. The Daily Telegraph, May 11 2012

Women using alternative contraception to the Pill 'are at double the risk of a blood clot'. Daily Mail, May 11 2012

Links To Science

Lidegaard Ø, Nielsen LH, Skovlund CS, Løkkegaard E. Venous thrombosis in users of non-oral hormonal contraception: follow-up study, Denmark 2001-10. BMJ. Published May 10 2012