Dr Amanda Mocroft and Michael Edwards, who is HIV-positive, writing in the magazine, said: "Most of the reduced mortality can be attributed to new treatments and the way in which treatments are combined."
The figures tally with similar studies done in the United States, where combination therapy - cocktails of different drugs taken at different times of the day - was introduced earlier than in Europe.
The researchers studied more than 4,000 HIV-infected patients, across 17 European countries and in Israel, between September 1994 and March 1998.
The researchers said they needed more funding to keep up their studies to see what happened in the future, if death rates continued to fall or if the virus developed resistance to the drugs.
One of the unknowns about combination therapy was the long-term effect on the body of taking the drugs. Patients often found that the effectiveness of a particular combination of drugs would wear off and they would have to take a new mixture.
Mr Edwards said the side- effects of combination therapy varied according to each individual. Mr Edwards, who works at the Aids charity The London Lighthouse, and has been HIV-positive for four years, is reluctant to take combination therapy because of the side- effects. The Lighthouse has lost funding, partly due to the success of the drugs.
The recent fall in Aids deaths in Europe and the US is not reflected in other parts of the world, where the rate of infection also continues to climb.
A recent report by the World Health Organisation and Unaids, the United Nations Aids organisation, said that HIV infection rates had risen by 10 per cent in the past year, bringing the number of HIV-positive people in the world to more than 33 million.
Few people in developing countries can afford the new drug treatments, which are expensive. This means Aids is still the leading cause of premature death worldwide.Reuse content