Press releases Monday 19 July to Saturday 24 July 2010

Please remember to credit the BMJas source when publicising an article and to tell your readers that they can read its full text on the journal's website (http://www.bmj.com).

(1) HPV vaccine gives prolonged protection against genital warts and low-grade pre-cancerous growths
(2) Preterm births higher among overweight and obese mothers
(3) Study finds large disparity in access to kidney transplants for UK patients
(4) Inequalities in mortality in Britain today greater than those during 1930s' economic depression

(1) HPV vaccine gives prolonged protection against genital warts and low-grade pre-cancerous growths
(Research: Four year efficacy of prophylactic human papillomavirus quadrivalent vaccine against low grade cervical, vulvar, and vaginal intraepithelial neoplasia and anogenital warts: randomized controlled trial)

Vaccination against certain types of human papillomavirus (HPV) gives strong and sustained protection against genital warts and pre-cancerous growths of the cervix, according to a new study published on bmj.com today.

An international study found that the quadrivalent HPV vaccine is helpful in preventing warts and low grade lesions related to HPV (types 6, 11, 16 and 18).

HPVs are responsible for around 500,000 cases of cervical cancer a year globally and 10 million further cases of high grade cervical intraepithelial neoplasia, which are immediate precusors to malignant cancerous growths.

In addition, it is estimated that 30 million women and men acquire anogenital warts (known as condyloma acuminata) or low-grade cervical growths each year.

The vaccine for HPV types 6, 11, 16 and 18 has the potential to prevent about 70% of cervical cancers and 90% of genital warts, but what contribution the vaccines make to low grade growths is still uncertain.

So an international group of investigators set out to find how useful the vaccines were in preventing low grade disease.

They studied results from 17,622 women aged 16-26 enrolled into two studies between December 2001 and May 2003. The women were enrolled from primary care centres and university or hospital associated health centres in 24 countries and territories around the world.

The women were split at random into two groups - one group was given three doses of HPV vaccine (for types 6, 11, 16 and 18) at day 1, month 2, and month 6 of the study, while the other women were given a placebo.

Results showed that amongst previously unexposed women who had received the vaccine, it was highly effective (96-100%) for preventing low grade lesions attributable to HPV types 6, 11, 16 and 18 for up to four years.

It also had considerable effectiveness against any lesion (regardless of HPV type), with a reduction of 30% of cervical low-grade growths, 48% of vulvar and 75% of vaginal low-grade growths. Genital warts were reduced by 83%.

The authors say the prolonged effectiveness of the vaccine in preventing low grade lesions is important and conclude: "These lesions occur shortly after infection and a reduction in these lesions will be the earliest clinically noticeable health gain to be realised by HPV vaccination.

"Low-grade cervical and vulvovaginal lesions are important from a public health perspective, as the diagnosis, follow-up, and treatment of these common lesions are associated with substantial patient anxiety, morbidity, and healthcare costs."

Contact:
Joakim Dillner, Professor of Virology and Molecular Epidemiology, Lund University, Malmö University Hospital, Malmö, Sweden
Email: joakim.dillner@med.lu.se

(2) Preterm births higher among overweight and obese mothers
(Research: Maternal overweight and obesity and the risk of preterm birth and low birth weight: systematic review and meta-analysis)

Overweight and obese women are at greater risk of giving birth to a preterm baby compared with normal weight women, finds a study published on bmj.com today.

The authors believe that overweight and obese women should have counselling before pregnancy so that they are aware of these risks and can try to modify their weight before pregnancy. They also stress the need for appropriate surveillance by health professionals during pregnancy.

Overweight and obesity is now the most common pregnancy complication in many developed countries and also some developing countries. For example, in the United Kingdom, 33% of pregnant women are overweight or obese. In India, 26% of pregnant women are overweight and a further 8% are obese, while in China, 16% are overweight or obese.

Preterm birth and low birth weight are the leading causes of infant death and illness throughout childhood. However, there is still uncertainty about the impact of a mother's weight on both preterm birth and low birth weight.

So a team of researchers in Canada analysed the results of 84 studies to assess the effect of maternal weight on preterm birth (before 37 weeks) and low birth weight (below 2500g) in singleton pregnancies in both developed and developing countries.

They found that the overall risk of preterm birth before 37 weeks was not significantly different among overweight or obese women compared with normal weight women.

However, there was a 30% increased risk of induced preterm birth before 37 weeks among overweight or obese women after accounting for publication bias, which is the tendency for studies to be published only if their results are positive. The heavier the woman, the higher the risk of induced preterm birth before 37 weeks, with very obese women at 70% greater risk than normal weight women.

Overweight or obese women also had a higher risk of early preterm birth (before 32 or 33 weeks). Again, the heavier the woman, the higher the risk of early preterm birth, with very obese women at 82% greater risk than normal weight women.

Although overweight or obese women had a lower risk of delivering a low birth weight baby than normal weight women, especially in developing countries, this effect disappeared after publication bias was taken into account. "Clinicians need to be aware that maternal overweight or obesity is not protective against low birth weight and consider surveillance when indicated," warn the authors.

"Ideally, overweight or obese women should have pregnancy counselling so that they are informed of their perinatal risks and can try to optimise their weight before pregnancy," they conclude.

Contact:
Sarah McDonald, Associate Professor, McMaster University, Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, McMaster University, Hamilton, Ontario, Canada
Email: mcdonals@mcmaster.ca

(3) Study finds large disparity in access to kidney transplants for UK patients
(Research: Variation between centres in access to renal transplantation in UK: longitudinal cohort study)

Large variations exist in access to kidney transplants for patients in the UK, which cannot be explained by case mix (differences in a patient's condition), according to a new study published on bmj.com today.

UK researchers found significant variations in access to the renal transplant waiting list, time to inclusion on the waiting list, and receipt of a renal transplant. They call for more research to understand if this is due to differences in resources or because some centres are better organised.

Outside the UK, many patient specific factors including age, sex, ethnicity and comorbidity have been reported to influence access to kidney transplantation.

Despite guidelines to assess patients' suitability for transplantation, individual clinicians and centre practices may vary in the interpretation of such guidelines and in the UK there has been little research into what impact these differences make.

Researchers from the UK Renal Registry and NHS Blook and Transplant (formerly UK Transplant), both in Bristol, studied data on 16,202 renal replacement therapy patients from 65 renal centres in the UK.

Information on these patients had been submitted to the UK Renal Registry between January 2003 and December 2008.

The researchers set out to evaluate whether there was equity of access to the renal transplant list for patients with end stage renal disease across the UK, whether centres differ in the time taken to activate suitable patients on the waiting list, and whether equity exists in the receipt of a renal transplant once the patient is on the transplant list.

The study also looked at "time to wait-listing" which was the interval between start of renal replacement therapy (kidney dialysis) and date of activation on the waiting list.

The national average percentage of patients registered for transplantation within two years of starting renal replacement therapy is 50%, but the study found that varied between around 25% in some centres and as much as 65% in others.

Although the national average percentage of patients receiving a kidney from a brain dead donor within two years of being registered for transplantation is 24%, the study found centres varied between 6% and 42%.

Centres were not to blame for this variability, however, as in this scenario, the national allocation policy determines where kidneys from brain dead donors should be sent.

The national average for the percentage of patients receiving a donor after cardiac death or a living kidney donor transplant within two years of being registered for transplantation is 25%, but the proportion of people receiving a kidney in this way ranged from less than 10% at some centres to above 40% in others.

There was also significant variation between centres in time to inclusion on the national transplant waiting list.

The researchers conclude: "Further work needs to be undertaken to understand whether the observed differences in centre performance are due to variations in resource availability or because certain centres have more organised and efficient patient pathways."

Contact:
Rommel Ravanan, consultant nephrologist, Richard Bright Renal Unit, Southmead Hospital, Bristol, UK
Email: rommel.ravanan@nbt.nhs.uk

(4) Inequalities in mortality in Britain today greater than those during 1930s' economic depression
(Research: Inequalities in premature mortality in Britain: observational study from 1921 to 2007)

The level of inequalities in premature mortality between different areas of Britain has almost surpassed those seen shortly before the economic crash of 1929 and the economic depression of the 1930s, according to a new study published on bmj.com today.

Inequalities continued to rise steadily during the first decade of the twenty first century, UK researchers have found, and could become worse.

Inequalities in mortality in Britain have persisted over many years and recent government efforts to reduce them have not had any great impact as yet. The gap in health inequalities has widened over the past 10 years, reflecting widening inequality in wealth and income.

Researchers from the universities of Sheffield and Bristol have built on previous research looking at socioeconomic differences in mortality, using updated population estimates and a new more accurate way of measuring poverty.

They analysed mortality data for England and Wales, obtained from the Office for National Statistics, and for Scotland, obtained from the General Register Office for Scotland.

The statistics for the entire population aged under 75 from 1990 to 2007 were used and the whole population aged under 65 from 1921-39, 1950-53, 1959-63, 1969-73 and 1981-2007.

The study found that geographical inequalities in age-sex standardised rates of mortality below age 75 have increased every two years from 1990-1 to 2006-7 without exception.

During this period, the poorest people were 1.6 times more likely to die prematurely than the most affluent people in 1990-1, and this difference increased so that by 2006-7, the worst off people were twice as likely to die prematurely than the most affluent people.

There was a small reduction in inequalities around 2001, but this trend quickly reversed and inequalities up to the age of 75 have now reached the highest levels reported since at least 1990.

A slight improvement in inequalities in mortality ratios was also noted in 2001 for people aged under 65, but this pattern has also reversed.

Historical records allow crudely age-sex standardised rates below age 65 to be compared and these reveal that geographical inequalities in mortality are higher in the most recent decade than in any similar time period for which records are available since at least 1921.

This means that the last time that inequalities were almost as high as they are now was in the lead up to the economic crash of 1929 and the economic depression of the 1930s.

The researchers conclude: "Although life expectancy for all people is increasing, the gap between the best and worst districts is continuing to increase. The economic crash of 2008 might precede even greater inequalities in mortality between areas in Britain."

Contact:
Lauren Anderson, University of Sheffield Media Team
Email: l.h.anderson@sheffield.ac.uk

Bethan Thomas, Research Fellow, Social and Spatial Inequalities Group, Department of Geography, University of Sheffield, UK
Email: b.s.thomas@sheffield.ac.uk

FOR ACCREDITED JOURNALISTS

For more information please contact:

Emma Dickinson
Tel: +44 (0)20 7383 6529
Email: edickinson@bma.org.uk

Press Office telephone : 020 7383 6254 (Weekdays : 0900hrs - 1800hrs)
British Medical Association
BMA House, Tavistock Square, London WC1H 9JP

and from:

the EurekAlert website, run by the American Association for the Advancement of Science (http://www.eurekalert.org)
[[$FOOTER]] http://intranet.bmj.com/departments/dept-bmj/bmj-team-resources/web-team-resources/General_blogging_principles.doc