Press releases Monday 6 June to Friday 10 July 2009
Please remember to credit the BMJ
as source when publicising an article and to tell your readers that they can
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(1) Study recommends statins for healthy people at risk of heart disease
(2) Government-backed youth programme pilot didn't reduce teenage pregnancies
(3) One in three breast cancers detected in women offered screening is overdiagnosed
(4) Gene defect linked to allergy
(5) Balance training prevents ankle sprains
(1) New heart disease risk score should be recommended in the UK, say experts
(Research: An independent external validation and evaluation of QRISK cardiovascular risk prediction: a prospective open cohort study)
http://www.bmj.com/cgi/doi/10.1136/bmj.b2584
(Editorial: QRISK or Framingham for predicting cardiovascular risk?)
http://www.bmj.com/cgi/doi/10.1136/bmj.b2673
A new score for predicting a person's risk of heart disease performs better than the existing test and should be recommended for use in the United Kingdom by the National Institute for Health and Clinical Excellence (NICE), say researchers in a paper published on bmj.com today.
But NICE currently recommends that doctors use a modified version of the long established score (known as the Anderson Framingham model) to identify who should be offered statin treatment to reduce their risk of heart disease over the next 10 years.
In 2007, the BMJ published research showing that the new QRISK score was a more accurate measure of how many UK adults are at risk of developing heart disease and which adults are most likely to benefit from treatment compared with the Framingham model.
Now, two independent experts from the University of Oxford have compared the performance of the two scores for predicting the 10 year cardiovascular disease risk in over one million UK patients.
They tracked the progress of 1.07 million patients registered at 274 general practices in England and Wales for up to 12 years after first diagnosis of cardiovascular disease. All participants were aged between 35 and 74 at the start of the study.
They found that, on every performance measure, QRISK gave a more accurate prediction of 10 year cardiovascular disease risk compared with Framingham. For example, the rate of cardiovascular disease events among men was 30.5 per 1000 person years in high risk patients identified with QRISK and 23.7 per 1000 person years in high risk patients identified with Framingham. Similarly, the rate of cardiovascular disease events among women was 26.7 per 1000 person years in high risk patients identified with QRISK compared with 22.2 per 1000 person years in high risk patients identified with Framingham.
In other words, QRISK identified a group of high risk patients who will go on to experience more cardiovascular events over the next 10 years more accurately than a similar high risk group identified by Framingham, say the authors.
This finding is probably not surprising, they add, as QRISK was developed on a separate but equally large cohort of patients in the UK and is thus more tailored to the UK population. Furthermore, QRISK contains additional risk factors - social deprivation, body mass index, family history, and current treatment with blood pressure drugs - which are known to affect cardiovascular disease risk and that are not included in either of the Framingham equations.
Despite some criticisms about missing data in the development of QRISK, the authors conclude QRISK performs better than the Anderson Framingham risk score in terms of identifying a high risk population for cardiovascular disease in the UK. Based on this evidence, they support the use of QRISK in favour of Anderson Framingham
This view is reiterated by researchers from the University of Auckland, in an accompanying editorial.
However, they point out that QRISK is just the first of many continuously updateable prediction algorithms that will become available as electronic health records replace current paper based systems. They also point to concerns regarding commercial restrictions to the use of the algorithm, and suggest that freely sharing these data is more likely to facilitate their effective implementation.
Although there is a small charge for commercial use of QRISK (which is designed to ensure correct implementation and quality control with revenues going towards research, support and development), use of the software is free for academics, research, teaching, educational use and personal use www.qrisk.org
Contact:
Research: Julia Hippisley-Cox, Professor of Clinical Epidemiology and Clinical Practice, University of Nottingham, Nottingham, UK
Email: julia.hippisley-cox@nottingham.ac.uk
Editorial: Rod Jackson, Professor of Epidemiology, School of Population Health, University of Auckland, New Zealand
Email: rt.jackson@auckland.ac.nz
A government-backed youth development pilot programme in England, aimed at reducing teenage pregnancies, drunkenness or cannabis use, didn't reduce teenage pregnancies and other outcomes and might have increased pregnancies, according to research published on bmj.com today.
The authors, led by Meg Wiggins of the Institute of Education, University of London and Chris Bonell at the London School of Hygiene and Tropical Medicine, were commissioned by the Department of Health to carry out an independent evaluation of the Young People's Development Programme (YPDP) in England.
Initiated in 2004, YPDP was informed by the US Children's Aid Society-Carrera programme which significantly reduced teenage pregnancies in disadvantaged areas of New York city. However, a 2005 study of attempted replications elsewhere in the United States did not find such benefits and there have been calls for further evaluation.
The study included over 2,500 young people aged 13 to 15 years who were deemed by professionals to be vulnerable or at risk of teenage pregnancy, substance misuse, or school exclusion.
Participants were either taking part in YPDP (intervention group) or a youth programme not receiving YPDP funds (comparison group). Measures including pregnancy, weekly cannabis use, and monthly drunkenness were assessed at 18 months.
Key results reveal significantly more pregnancies among young women in the YPDP group than in the comparison group (16% versus 6%). Young women in the YPDP group also more commonly reported early heterosexual experience (58% versus 33%) and expectation of teenage parenthood (34% versus 24%).
Significantly more young people in the YPDP group also reported truanting in the previous six months than in the comparison group.
The authors found no definite explanation for the findings. For example, one obvious explanation is that young people in the YPDP group were more at risk at the start of the study, yet the authors show that YPDP group participants were no more sexually active than those in the comparison group and adjusted for other differences. Other plausible causes may involve participants being exposed to more risky peers and being labelled as problematic.
They conclude that any further implementation of such interventions in the UK should be only within randomised trials.
They also suggest that participants should be targeted by social disadvantage rather than behavioural risk and that wider socioeconomic and education influences on young people's health need to be addressed.
These results suggest that, at best, the programme had no impact, and at worst had a negative impact, says Douglas Kirby, a senior research scientist based in the United States.
But this does not mean that all youth development approaches are ineffective, he writes. For example, programmes may be more effective when implemented by charismatic staff, when they facilitate access to reproductive health services, when the staff connect with the teenage participants, or when the staff give a strong clear message about avoiding unprotected sex.
Furthermore, there is evidence that different types of youth development programs can have a positive impact on sexual risk behaviour and reported pregnancy rates.
Contacts:
Research: Helen Green, Press Office, Institute of Education, University of London, UK
Meg Wiggins, Senior Research Officer, Institute of Education, University of London, UK
Chris Bonell, Senior Lecturer, London School of Hygiene and Tropical Medicine, London, UK
Email: chris.bonell@lshtm.ac.uk
One in three breast cancers detected in a population with a public breast screening programme is overdiagnosed, conclude researchers in a paper published on bmj.com today.
Overdiagnosis refers to the detection of harmless cancers that will not cause symptoms or death during a patient's lifetime. This may be because the cancer grows so slowly that the patient dies of other causes before it produces symptoms, or the cancer remains dormant or regresses.
But because it is not possible to distinguish between lethal and harmless cancers, all detected cancers are treated. Overdiagnosis and overtreatment are therefore inevitable.
So to estimate the extent of overdiagnosis, Karsten Jørgensen and Peter Gøtzsche at the Nordic Cochrane Centre analysed breast cancer trends before and after the introduction of publicly organised screening programmes in five countries (UK, Canada, Australia, Sweden and Norway).
To minimise bias, their data covered at least seven years before screening and seven years after screening had been fully implemented in each country, and included both screened and non-screened age groups.
They also took account of other factors that may have affected the results, such as changes in background levels of breast cancer and any compensatory drop in rates of breast cancer among older, previously screened women.
They found an increase in incidence of breast cancer that was closely related to the introduction of screening and little of this increase was compensated for by a drop in incidence of breast cancer in previously screened women.
They then estimated the level of overdiagnosis for each country. For the UK they estimated 57% overdiagnosis, for Manitoba 59%, for New South Wales 53%, for Sweden the estimate was 46% and for Norway it was 52%.
They estimated a total overdiagnosis of 52%. This included carcinoma in situ (a pre-malignant condition) as it is generally treated in the same way as invasive breast cancer. For invasive breast cancer only, the over-diagnosis was 35%.
This means that one in three breast cancers detected by public breast screening programmes are overdiagnosed, say the authors.
Here is an example to help explain how these figures were reached. Overdiagnosis refers to the difference between the observed versus the expected incidence of breast cancer. If the expected incidence (based on pre-screening trends) is 200 per 100,000 women, but the observed incidence is 300 per 100,000 women then the increase over expected is 100 per 200 (or 50%). So 100 per 100,000 of 300 per 100,000 observed incidence represents overdiagnosis. In other words one in three breast cancers are overdiagnosed.
These results are consistent with a growing body of evidence that screening mammography is associated with sustained increases in the incidence of breast cancer in women of screening age, with little or no subsequent decrease in incidence in older women, writes Professor H. Gilbert Welch in an accompanying editorial.
Mammography undoubtedly helps some women but hurts others, he adds. No right answer exists, instead it is a personal choice.
To inform that choice, he suggests women need a simple tabular display of benefits and harms based on the latest evidence (see link to table below). Careful analyses to improve the precision of these estimates are also needed.
Finally, he suggests that researchers need to do more than just describe the problem. They need to work towards mitigating it by testing higher thresholds, such as only recommending biopsy for breast masses larger than a certain size, in a randomised trial.
Contacts:
Research: Karsten Jørgensen, Nordic Cochrane Centre, Rigshospitalet Department, Copenhagen, Denmark
Email: kj@cochrane.dk
Defects in a particular gene (the filaggrin gene) are associated with a significantly increased risk of developing allergic disorders such as eczema, rhinitis, and asthma, concludes a study published on bmj.com today.
Allergic diseases have increased in recent decades and now affect up to one in three children in economically developed countries. For many years researchers have looked for genes that might contribute to allergic diseases but, until recently no major associations had been described, and a real "allergy gene" was elusive.
However, recent reports have consistently pointed to a strong influence of the filaggrin gene in maintaining an effective skin barrier against the environment.
So researchers at the University of Edinburgh analysed the results of 24 studies to investigate if filaggrin gene mutations increase the risk of developing allergic sensitisation and allergic disorders.
Differences in study quality were taken into account to identify and minimise bias.
Pooling the results showed that filaggrin gene mutations significantly increase the risk of developing allergic sensitisation, atopic eczema, allergic rhinitis, and asthma in people with eczema. The relationship between filaggrin gene mutations and atopic eczema was particularly strong.
Filaggrin gene mutations also increased the risk of asthma in people with atopic eczema.
"These findings provide strong supporting evidence that, at least in a subset of those with allergic problems, the filaggrin gene defect may be the fundamental predisposing factor not only for the development of eczema but also for initial sensitisation and progression of allergic disease,” say the authors.
"Our finding suggest that filaggrin is a robust biomarker for allergic conditions," they add.
Further studies now need to explore whether filaggrin can be used to identify those at high risk. Restoring skin barrier function in filaggrin deficient people in early life may also help prevent the development of sensitisation and halt the development and progression of allergic disease, they conclude.
This study represents an important breakthrough in understanding the genetic basis of this complex disorder, say experts from Singapore in an accompanying editorial. The next challenge will be to distinguish different genotypes of allergy, which could revolutionise the prevention, diagnosis, and treatment of allergy in children, they conclude.
Contacts:
Research: Professor Aziz Sheikh, Professor of Primary Care Research and Development, Centre for Population Health Sciences, University of Edinburgh, UK
Email: Aziz.sheikh@ed.ac.uk
(5) Balance training prevents ankle sprains
(Research: Effect of unsupervised home based proprioceptive training on recurrences of ankle sprain: randomised controlled trial
http://www.bmj.com/cgi/doi/10.1136/bmj.b2684
A simple training programme, based on a series of balancing exercises, can cut the risk of recurrent ankle sprains by 35% and could lead to huge savings in medical and lost productivity costs, concludes a study published on bmj.com today.
Ankle sprains are one of the most common and costly sports injuries. In the United States, an estimated 23,000 ankle sprains occur every day, while in the Netherlands, an estimated 234,000 ankle sprains occur annually, costing over Euro 84,000,000.
There is also strong evidence that athletes are at high risk of re-injury in the first year after an ankle sprain, with half of these leading to chronic pain and disability requiring prolonged medical care.
So researchers in the Netherlands assessed the effectiveness of an unsupervised home-based training programme consisting of a series of exercises to improve balance and motor coordination skills (known as proprioception abilities).
A group of 522 athletes (274 men and 248 women) aged between 12 and 70 years, from a wide range of sports, were randomly split into two groups. Both groups received treatment according to usual care. The intervention group (256 athletes) also received an eight-week home-based proprioceptive training programme.
The programme consisted of three 30-minute training sessions per week. Athletes were encouraged to perform the exercises as part of their warm-up of their normal sporting activity. Exercises gradually became more difficult during the eight-week programme.
All participants were monitored for one year. During this time, 145 athletes reported an ankle sprain recurrence: 56 (22%) athletes in the intervention group and 89 (33%) in the control group.
The intervention programme was associated with a 35% reduction in the risk of recurrent ankle sprains compared to the control group, of which most was ascribed to non-medically treated athletes.
One ankle sprain recurrence was prevented for every nine athletes who completed the programme.
These results show that an eight-week unsupervised home-based proprioceptive training programme is effective in preventing ankle sprain recurrences after usual care, say the authors. This training programme was specifically beneficial in athletes whose inclusion ankle sprain was not medically treated.
Contacts:
Professor Willem van Mechelen, Department of Public and Occupational Health, EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands
Email: w.vanmechelen@vumc.nl
FOR ACCREDITED JOURNALISTS
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Tel: +44 (0)20 7383 6529
Email: edickinson@bmj.com
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and from:
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