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Press releases Saturday 22 March 1997
Embargo: Friday 21 March 00.01 Hrs

HIV drug trials in South Africa - short term relief or long term exploitation?

[Availability of antiretroviral therapy after clinical trials with HIV-infected patients are ended]

The ethical dilemma posed by trials of HIV drugs in poorer countries is discussed in a number of papers in this week's BMJ. Professor Peter Cleaton-Jones, Chairman of the Committee for Research on Human Subjects at the University of the Witwatersrand, South Africa, discusses the responsibility of pharmaceutical companies to continue to provide treatment to those who are benefiting from it after the end of a trial.

South Africa has a high prevalence of HIV infection - in some parts of the country up to 14% and rising - and proven medical expertise. It is therefore an attractive location for trials of new treatments by multinational drug companies, says the author. With most diseases, continuation of treatment after the end of the trial is not a problem because effective alternative therapies are available. But when no other treatment is available, what should be done?

The emergence of combination therapy for HIV has altered company rules, says the author. Companies must often purchase another manufacturer's drug to use in conjunction with their own, and they will usually continue to provide their trial drug until it is commercially available, or provide zidovudine (AZT) alone. "Since combination therapy is the current optimal treatment," asks the author "can ethics committees allow patients to revert back to a less effective treatment?" And if a drug becomes commercially available, "is it ethical to halt treatment knowing that neither the health service nor trial subject can afford it?"

Trial investigators fall into two camps, says Professor Cleaton-Jones. Some will not undertake trials unless there is an arrangement for their patients to receive drugs long term. Others, knowing that their patients would normally receive no treatment at all, believe that two to three years of drug therapy is at least of some benefit and may buy time for future breakthroughs.

The level of illness currently required for inclusion in HIV trials is such that many subjects do not survive past the trial period. "Surely," says the author "agreement can be made on a response to the trial drugs so that only those responding may continue treatment."

Commentaries on the same subject from a South African representative of a HIV patient advocacy group, an HIV trial centre in Australia, a senior lecturer in the Department of Philosophy at Witwatersrand, and the senior medical adviser to Roche Products in the UK, discuss the moral responsibility of pharmaceutical companies in such trials and the need for effective partnership with patient groups.

Contact:
Prof Peter Cleaton-Jones
University of Witwatersrand
Johannesburg
South Africa

Tel: 00 27 11 716 4030
Fax: 00 27 11 716 8030

Breast cancer screening probably works

[Effectivess of the public health policy for breast cancer screening in Finland: population based cohort study]

Giving blood may offer some protection against heart attacks reports a study in this week's BMJ.

In 1987, Finland became the first country in the world to introduce a nationwide breast cancer screening programme. In this week's BMJ, a group of Finnish scientists report on its effectiveness in preventing deaths.

The scientists studied the records of nearly 90,000 women invited for screening, and compared them with nearly 70,000 who had not been screened. They found that about 200,000 screening tests had prevented 20 deaths, and ask - was the effect large enough to justify the time and resources spent on this public health policy?

The screening programme has effects other than reductions of breast cancer deaths, and these should be taken into account when deciding whether to introduce such a programme, say the authors. Most women in Finland attend breast cancer screening clinics for reassurance, and the effect on their quality of life through, for example, breast conserving surgery, should not be dismissed. If no screening programme exists, the resources will go elsewhere. Breast cancer screening is cost effective compared with many other health care services, conclude the authors.

Contact:
Dr Matti Hakama
University of Tampere
Tampere
Finland

Tel: 00 358 3 2156111
Fax: 00 358 3 2156057
(Tuesday and Thursday)

Tel: 00 358 9 135331
Fax: 00 358 9 1355378
(Wednesday and Friday)

Health hazards of sleep apnoea exaggerated

[Health effects of obstructive sleep apnoea and the effectiveness of continuing positive airways pressure: a systematic review of the research evidence]

[Snoring and breathing pauses during sleep: telephone interview survey of a United Kingdom population sample]

Two papers in this week's BMJ look at the problem of obstructive sleep apnoea (the periodic reduction or cessation of breathing during sleep due to narrowing of the upper airways).

According to the New England Journal of Medicine, this may be as big a public health hazard as smoking. But a large-scale review of research papers on the subject reveals that it may not be a disease at all.

Dr. John Wright, from Bradford Royal Infirmary, and colleagues from the NHS Centre for Reviews and Dissemination, York, report the conclusions of their study of 54 papers examining the association between sleep apnoea and other health problems, for example hypertension, heart disease and stroke. They found little evidence to back up the view that it is an important cause of death and disability, although they conclude that it does cause daytime tiredness and reduction in attention.

The most common treatment for sleep apnoea is continuous positive airways pressure (a bedside ventilator which maintains clear breathing), say the authors, but this only leads to a small reduction in daytime sleepiness. Because being overweight appears to be a major factor in its development, greater emphasis sbould be given to weight loss programmes in the reduction of sleep apnoea.

Although the relevance of sleep apnoea to public health has been exaggerated, say the authors, there is enough evidence of the benefit of reducing day-time sleepiness to warrant large randomised trials of positive airways pressure versus weight loss and other programmes.

In another study of nearly 5,000 British adults, forty percent reported snoring regularly and 3.8% had breathing pauses during sleep. Dr. Maurice Ohayon, Professor Robert Priest and colleagues found that snoring tended to be more common among men than women,and that obesity, smoking, night-time awakening and consuming large amounts of caffeine were also implicated.

Breathing pauses were also more common among men, and were associated with thyroid disease and the taking of anxiety reducing drugs. Both snoring and breathing pauses were associated with drowsiness while driving. Obstructive sleep apnoea was associated with being an obese man, with higher blood pressure, and daytime sleepiness.

Disordered breathing during sleep is widely underdiagnosed in the UK, conclude the authors, and the resulting daytime sleepiness increases the risk of accidents. To their surprise, this sleep disorder was as often labelled 'daytime sleepiness' as 'insomnia'. A diagnosis of insomnia may preclude recognition of a sleep-related breathing problem and lead to inappropriate and possibly harmful treatment with anti-anxiety drugs, they say.

Contact:
Dr John Wright
Bradford Royal Infirmary
Bradford
West Yorkshire

Tel: 01274 364279
Fax: 01274 364996

Professor Robert Priest
Emeritus Professor
St. Mary's Hospital
London

Tel: 01753 653178
Fax: 01753 651314

What makes doctors change their behaviour?

[Why general practitioners and consultants change their clinical practice: a critical incident study]

Keeping up to date with changes in clinical practice is an important part of continuing education for doctors. But studying whether or not and how they do so, and what is the most effective way of ensuring that they do, is difficult.

A paper in this week's BMJ looks at the range of factors which might be involved in implementing changes in clinical practice, and seeks to clarifiy the role of education in bringing about such change.

50 GPs and 50 consultants were asked to describe changes they had made in four areas of their clinical practice, including management of a common illness or condition, and what had led to the changes being made. The average number of reasons per change was three, says the report. Education was involved in about a third of the changes - consultants mentioned reading medical journals and attending scientific conferences in this regard, while GPs tended to be more influenced by medical newspapers and postgraduate meetings.

While GPs reported that they were influenced both by consultants and hospital organisation, there is little evidence of influence in the other direction. A future role for education could be to aid two-way learning between consultants and GPs, says the report.

But changes in clinical practice are due to a combination of factors, say the authors, and the reasons for change are numerous and wide-ranging. "Education should not be regarded as a stand-alone activity" say the authors. They recommend that organisers of educational events should, rather than investigate whether the event on its own led to a change, look at whether it was only one of a number of factors for the change. "This approach is essential if the effectiveness of continuing medical education is to be established" they say.

Contact:
Lynne Allery
University of Wales
College of Medicine
Cardiff

Tel: 01222 743302
Fax: 01222 754966
email: allery@cf.ac.uk

EMBARGO: 00.01 HRS Friday 21 March 1997

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