Although precise figures are not yet available, in Avon - which previously had one of the highest death tolls - there was not a single unexplained death of a baby under one year from March 1992 to February this year.
Dr Peter Fleming, a world expert on the Sudden Infant Death Syndrome, disclosed yesterday that preliminary results showed cuts overall of '50 per cent and possibly more'.
He is a leading member of the Institute of Child Health at Bristol University, which yesterday announced a pounds 115,000 investigation into further possible benefits from the change in the sleeping position for babies.
It is being funded by the Department of Health and by the Anne Diamond Cot Death appeal - set up after the television presenter's four-month-old son Sebastian died from the syndrome in July 1991.
Professor Jean Golding, of the institute, explained: 'We are seeing a dramatic effect on cot deaths from the change in sleeping position. It raises the question, what else may be happening? It may be that other childhood diseases could be beneficially affected by this basic change in behaviour.'
The practice of putting babies to sleep on their fronts was widespread until the mid-1980s. Then Dr Fleming's research team revealed an association between cot deaths and sleeping position.
A campaign in Avon in October 1991 was quickly followed by the national campaign, funded by the Foundation for the Study of Infant Deaths and the Department of Health's Back to Sleep campaign.
The institute has closely monitored the impact of the national campaign.
Dr Fleming said: 'Avon had one of the highest cot death rates in the country with an average of 40 deaths a year in the late 1980s. Now the figures have plummeted. Preliminary results from other regions are also showing dramatic reductions.'
Before the campaign cot deaths claimed about 1,500 infants a year in Britain.Reuse content