This week's embargoed articles may not be available until 09:00 (UK time) Thursday.
Press releases Monday 5 January 2009 to Friday 9 January 2009
Please remember to credit the BMJ as source when publicising an article and to tell your readers that they can read its full text on the journal's web site (http://www.bmj.com).
(1) Deaths from lung cancer could be reduced by better policies to control indoor radon
(2) Behavioural difficulties at school may lead to lifelong health and social problems
(3) Newborn screening test could increase early detection of heart disease and save lives
(4) New tests needed to predict cardiovascular problems in older people more accurately
(1) Deaths from lung cancer could be reduced by better policies to control indoor radon
(Research paper: Lung cancer deaths from indoor radon and the cost-effectiveness and potential of policies to reduce them)
http://www.bmj.com/cgi/content/full/338/jan06_1/a3110
(Editorial: Indoor radon and deaths from lung cancer)
http://www.bmj.com/cgi/content/full/338/jan06_1/a3128
About 1100 people each year die in the UK from lung cancer related to indoor radon, but current government protection policies focus mainly on the small number of homes with high radon levels and neglect the 95% of radon related deaths caused by lower levels of radon, according to a study published on bmj.com today.
The authors argue that installing basic and cheap measures to prevent radon in all new homes would be more cost-effective and have greater potential for reducing lung cancer deaths caused by radon, and UK Building Regulations should be amended to enforce this.
Radon in the home is a natural air pollutant produced by the decay of uranium in the ground. Radon gas seeps into buildings through cracks and holes in the foundations and when it decays it produces particles that can enter the lungs and expose them to damaging radiation.
At present, government policies in the UK concentrate on searching for homes with high levels of radon and encouraging homeowners to take remedial action at their own expense.
Professor Alastair Gray, Professor Sarah Darby and other colleagues from the University of Oxford, assessed the contribution of indoor radon to lung cancer deaths in the UK, and examined the cost- effectiveness of policies to control radon exposure. They used recent evidence on the risk of lung cancer from indoor radon, based on data from 7,000 people with lung cancer and more than 21,000 people without lung cancer across Europe. They then calculated the lifetime risk of lung cancer death before and after various interventions to control radon, and the costs involved.
The authors estimate that 1100 deaths a year in the UK are related to radon, about 3.3% of all deaths from lung cancer, but less than 5% of radon related deaths occur from exposure above the current action level. In addition, they report that many homeowners refuse to have their home tested or to spend money reducing radon levels. As a result these policies are costly and have a minimal impact on radon related deaths.
In contrast, the authors found that installing simple preventive measures in new homes is highly cost-effective, but at present is only being done in selected areas of the country. This should be rolled out across the whole UK, say the authors, and should be backed up by changes to the Building Regulations. A gas-resistant membrane in the foundations would reduce radon by about 50% and would cost only about Ł100.
Importantly, the study also found that six out of seven radon related lung cancers occur in people who smoke or who have smoked in the past. The best way for current smokers to reduce risk is to stop smoking. Current and former smokers can also reduce their risk by taking radon control measures seriously, say the authors.
The authors suggest that their findings are relevant to many other countries, most of which have higher concentrations of radon than the UK. The average radon concentration in UK homes is 21 bequerels per cubic metre, but in the European Union the average is 55, suggesting that about 8% of deaths from lung cancer, or 18,000 deaths each year, are caused by radon across the EU.
This is the most extensive and detailed evaluation to date of the policies to counter radon-induced and deaths from lung cancer, say Professor Anssi Auvinen from the University of Tampere in Finland and Professor Göran Pershagen from the Institute of Environmental Medicine in Sweden, in an accompanying editorial.
The findings suggest that:“Radon policies need to be scrutinised [and particularly in populations with low average levels], the priority should be to apply basic measures universally rather than to take action only when high radon levels have been identified by measurement.”
Contacts:
Professor Alastair Gray, University of Oxford, Oxford, UK
Email: alastair.gray@dphpc.ox.ac.uk
Professor Sarah Darby, University of Oxford, Oxford, UK
Email: sarah.darby@ctsu.ox.ac.uk
(2) Behavioural difficulties at school may lead to lifelong health and social problems
(Research: Outcomes of conduct problems in adolescence: 40 year follow-up of national cohort)
http://www.bmj.com/cgi/doi/10.1136/bmj.a2981
Adolescents who misbehave at school are more likely to have difficulties throughout their adult lives, finds a 40-year study of British citizens published on bmj.com today. These difficulties cover all areas of life, from mental health to domestic and personal relationships to economic deprivation.
Severe behavioural problems in schools affect about 7% of 9–15 year olds and have been on the increase for the past 30 years. Previous studies have shown that individuals with severe conduct problems place a significant burden on society in terms of crime as well as the additional needs of education, health and welfare.
Ian Colman, an Alberta Heritage Foundation for Medical Research Population Health Investigator, and Assistant Professor at the University of Alberta’s School of Public Health, and his colleagues examined the health and social problems of adults who had mild and severe behavioural problems as adolescents. The findings are based on more than 3,500 individuals taking part in the Medical Research Council National Survey of Health and Development (the British 1946 birth cohort), over a 40-year period. All the participants were aged between 13 and 15 at the start of the study. Approximately a quarter of the participants had mild behavioural problems.
Participants were rated by their teachers as having severe, mild or no conduct problems and were followed up between the ages of 36 and 53 when they were asked about their mental health, and social and economic status.
The results reveal disturbing new information about the societal impact of milder behavioural problems.
They show that the participants with severe or mild conduct problems in adolescence were more likely to leave school with no qualifications and go on to suffer a number of problems in adulthood including depression and anxiety, divorce, teenage pregnancy, and financial problems that continued throughout adult life.
These results held true even after taking into account predictors of outcomes in adulthood such as sex, father’s social class, adolescent depression and anxiety and cognitive ability.
Interestingly, unlike previous studies in the field, these findings show that most of the participants who were badly behaved at school did not have alcohol problems as they got older.
Colman and his team conclude: “Given the long-term costs to society, and the distressing impact on the adolescents themselves, our results might have considerable implications for public health policy.”
For interviews with Dr Colman please contact:
Kathleen Thurber, Director of Communications, Alberta Heritage Foundation for Medical Research (AHFMR), Alberta, Canada
Tel: +1 780 423 5727 ext. 221
or
Tel: +1 780 492 0436
or
Tel: +1 780 492 1386
(3) Newborn screening test could increase early detection of heart disease and save livesRoutine screening of blood oxygen levels before discharge from hospital improves the detection of life threatening congenital heart disease in newborns and may save lives, according to a study published on bmj.com today.
The low false positive rate of pulse oximetry screening* and the reduced need for treatment because of a timely diagnosis also makes this a cost effective intervention, say the authors.
About 1–2 babies per 1000 live births have an immediately life threatening heart abnormality, because a fetal blood vessel called the ductus arteriosus - which bypasses the baby's non-functioning lungs when in the uterus and normally closes off soon after birth - remains partly open. The current screening technique of a routine clinical examination shortly after birth fails to detect many of these babies because duct-dependent heart disease often lacks heart murmurs. Indeed, 30% of such infants leave hospital without their condition being diagnosed, which leads to higher rates of complications such as circulatory collapse with organ damage and sometimes death.
Pulse oximetry screening has been suggested for early detection of congenital heart disease, but its effectiveness is unclear.
Professor Östman-Smith and colleagues assessed the introduction of universal oximetry screening in one region of Sweden (West Götaland) and examined the diagnostic accuracy for detection of duct dependent heart disease compared to other regions using clinical examination alone. Nearly 40,000 babies born between 1 July 2004 and 31 March 2007 were screened with a pulse oximeter before routine physical examination.
The authors found that in apparently well babies ready for discharge a combination of clinical examination and pulse oximetry screening had a detection rate of 82.8% for duct-dependent heart disease. The detection rate of physical examination alone was 62.5%. Pulse oximetry also had a substantially lower false positive rate (0.17%) compared to physical examination alone (1.90%).
However, some babies had been detected before discharge examination, meaning that the introduction of pulse oximetry screening in West Götaland improved the total detection of duct dependent heart disease to 92%. This was significantly higher than the 72% detection rate in other regions not using the screening technique. Thus the risk of leaving hospital with an undiagnosed duct dependent circulation was 8% in West Götaland versus 28% in the other regions.
Babies discharged from hospital without diagnosis had higher mortality than those diagnosed in hospital (18% v 0.9%). In addition, no babies died in West Götaland from undiagnosed heart disease, but there were five deaths in the other regions.
Interestingly, improved detection was achieved by a maximum of just five minutes of extra nursing time per baby.
The authors conclude: “Such screening seems cost neutral in the short term, but the probable prevention of neurological morbidity and reduced need for preoperative neonatal intensive care suggest that such screening will be cost effective long term.”
In an accompanying editorial, Professor Keith Barrington from the University of Montreal in Canada, says that in light of this new evidence on the effectiveness of universal pulse oximetry screening as a low risk and low cost strategy for improving the detection of critical congenital heart disease, “serious consideration should be given to its introduction wherever neonatal cardiac surgery is available.”
Notes to Editors:
*Pulse oximetry is a quick and non-invasive method of measuring the concentration of oxygen in the blood of newborns using a sensor placed on a hand, and in this study on a foot as well, for a few minutes before the baby leaves hospital. A low concentration of oxygen could signal a heart problem and would require further investigation.
Contacts:
Professor Ingegerd Östman-Smith, Queen Silvia Children’s Hospital and Sahlgrenska Academy, Gothenburg University, Göteborg, Sweden
Email: ingegerd.ostman-smith@pediat.gu.se
Editorial: Professor Keith Barrington, Université de Montréal, Quebec, Canada
Email: keith.barrington@mcgill.ca
A long-standing system for assessing the risk of cardiovascular disease amongst older people should be replaced with something more accurate, according to a study published today on bmj.com.
The Dutch study looked at several hundred people with no history of cardiovascular disease aged 85 over a five year period to see which of them died of cardiovascular disease (such as stroke and heart disease), and whether different ways of assessing their risk of such disease at the start proved to be more accurate.
The Framingham Risk Score system has been used for decades to predict the 10-year risk of developing coronary heart disease in people with no history of such disease. It uses classic risk factors including sex, systolic blood pressure, cholesterol, diabetes, and smoking.
The ability of these classic risk factors to identify a person at high risk of heart disease diminishes as the person gets older.
In recent times, several new biomarkers for cardiovascular disease have been shown to be effective at indicating high risk of such disease, including C-reactive protein and homocysteine.
The researchers studied 302 people aged 85 years old (215 men and 87 women) who had no history of cardiovascular disease. The people were taking part in the existing Leiden 85-plus Study and were followed up for five years.
As well as using the Framingham Risk Score, the researchers also measured plasma levels of the new biomarkers homocysteine, folic acid, C-reactive protein and interleukin-6 in the people.
During the follow-up period, 108 of the 302 participants died and 32% of the deaths were from cardiovascular disease.
The researchers found that classic risk factors were unable to predict cardiovascular deaths accurately, neither by using the Framingham Risk Score nor by using the classic risk factors in a newly calibrated model.
From the new biomarkers used, homocysteine had the best ability to predict deaths.
Of the 35 people who died from cardiovascular disease during the five years studied, the Framingham Risk Score had classified just 12 people as being at high risk. However, the homocysteine-based model had classified 20 people as being high risk—nearly a quarter more of all individuals who died from cardiovascular disease.
The authors conclude that a single homocysteine measurement can accurately identify very elderly people who are at high risk of dying from cardiovascular disease. They call for a larger study to be carried out as their findings could lead to a change to current guidelines.
The researchers say: “Possibly, plasma homocysteine, and not classic risk factors, could be used to select very elderly people for primary preventive interventions.”
Contact:
Dr Wouter de Ruijter, Leiden University Medical Center, The Netherlands
Email: w.de_ruijter@lumc.nl
FOR ACCREDITED JOURNALISTS
Embargoed press releases and articles are available from:
Public Affairs Division, BMA House, Tavistock Square London WC1H 9JR
(contact: pressoffice@bma.org.uk)
and from:
the EurekAlert website, run by the American Association for the Advancement of Science (http://www.eurekalert.org)
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