SURVIVAL AFTER AIDS DIAGNOSIS IN WASHINGTON-STATE - TRENDS THROUGH 1989 AND EFFECT OF THE CASE-DEFINITION CHANGE OF 1987

Survival analysis was performed for AIDS cases diagnosed in Washington state from 1982 through 1989 and reported through October 31, 1991. N o difference in survival time among diagnosis years 1987, 1988, and 19 89 (p = 0.29) was found. Since September 1987, survival time was longe st for cases with human immunodeficiency virus (HIV) wasting syndrome and HIV encephalopathy. Adjusted risk for death was significantly lowe r for these cases relative to all other cases (relative risk, 0.5; 95% confidence interval, 0.4-0.6). Explanations for the absence of contin uing increase in survival time between 1987 and 1989 include changes i n the frequency and timing of anti-HIV therapy. Longer survival time a mong cases diagnosed with HIV wasting or HIV encephalopathy is likely due to diagnosis earlier in the course of HIV disease. These results e mphasize how changes over time in the definition of AIDS and evolving therapeutic standards may affect assessment of survival time when usin g surveillance data.