However, the standards set by journal editors vary and many are little different from vanity publishers. There are a couple of dozen with a rigorous peer-review process and a reputation that give them clout on the medical world stage. It is safe to say that the Swedish journal Lakartidningen is not one of them.
In more than a decade of medical reporting I do not recall seeing this journal until last week when a study it published appeared in most British national newspapers. It was an analysis of the breast-screening programme introduced in Sweden in the late Eighties which showed that over 10 years there had been no significant fall in deaths from breast cancer.
If confirmed, this is important. Britain based its breast-screening on the Swedish model. We spend pounds 34m a year checking every woman aged 50-64 every three years for signs of breast cancer. Are we wasting our money and could we save more lives by improving treatment for breast cancer sufferers?
Worse, in the Swedish study more than 100,000 women had received a false positive diagnosis - a suspicious mammogram, causing anxiety and distress, which turned out later to be nothing serious. In the course of this, 16,000 women had unnecessary biopsies (samples of tissue taken from their breasts) and 4,000 had surgery to remove a lump - or in some cases the whole breast - which turned out to be healthy. This is a heavy price to pay even for a successful programme and if no lives are being saved then it is unacceptable.
But the Swedish journal, Lakartidningen is little known. So how did the study it published reach the British press? A news report of the study appeared in the "News" section of the British Medical Journal, which functions like a newspaper for doctors, alerting them to developments of interest in the medical world but without subjecting them to the peer-review applied to the journal's original papers. Health reporters scan these pages but somehow, we all missed the Swedish study reported in the March 6 edition of the BMJ until the medical editor of the Daily Mail, who had been on holiday, spotted it the following week. Her front-page story last week ran under the headline "Breast screening `doesn't prevent deaths'".
The story triggered a furious reaction from the National Breast Screening Service. Its press office, fearing a mass defection by women, called news organisations on Thursday morning to alert them to a highly critical letter posted on the BMJ's website. It was from Mans Rosen, deputy director general of the National Board of Health and Welfare in Stockholm which said the Swedish research would not have passed the peer review process for the BMJ or "other distinguished journals". It added that the board had no intention of changing its advice on breast screening "based on such a defective study".
So where does this leave women? The UK breast screening service maintains that at least 1,000 lives a year are being saved although it admits that it will be a year or two more before definitive evidence of this is available. The Swedish researchers maintained that the disparity between the clinical trials of screening, which suggested up to 30 per cent of deaths could be prevented, and the lack of success of the programme reflected the difficulty in spreading a technique nationwide.
This is what lies at the heart of this issue. An idea may work when pioneered in a few centres by highly motivated enthusiasts with exceptional skills. But when run nationally it is only as good as its weakest link. At the moment, breast screening appears to be one of the better programmes and women aged over 50 would be advised to attend for a regular check. But no one can say for certain that it is working until those definitive figures are in.