COMPARISON OF LONG-TERM PROGNOSIS OF PATIENTS WITH AIDS TREATED AND NOT TREATED WITH ZIDOVUDINE

Objective.-To determine the association between elapsed time since sta rting zidovudine and survival in patients with acquired immunodeficien cy syndrome (AIDS). Design.-Inception cohort and observational study o f patients treated and not treated with zidovudine. Setting.-Fifty-one centers in 17 European countries. Patients.-A total of 4484 patients diagnosed as having AIDS from 1979 to 1989 who survived their initial AIDS-defining event and who had not started zidovudine before AIDS dia gnosis. Main Outcome Measures.-Use of zidovudine and mortality. Result s.-Among patients who did not receive zidovudine, the death rate was a pproximately constant for the first 5 years after AIDS diagnosis. For patients treated with zidovudine, the death rate within the first year since starting zidovudine was markedly lower than for untreated patie nts who had developed AIDS at the same time (relative rate, 0.47; 95% confidence interval [CI], 0.42 to 0.51). For longer times since starti ng zidovudine, the association with reduced mortality rate was diminis hed, and for patients surviving more than 2 years since starting zidov udine, the death rate was greater than for untreated patients who had developed AIDS at the same time (relative rate, 1.35; 95% CI, 1.15 to 1.58). Adjustment for other prognostic factors failed to substantially affect this observation. Conclusions.-When initiated after the time o f AIDS diagnosis, zidovudine was associated with improved prognosis bu t for no more than 2 years after starting therapy.