Hoover D R, Muñoz A, He Y, Taylor J M, Kingsley L, Chmiel J S, Saah A
Department of Epidemiology, Johns Hopkins School of Public Health, Baltimore, MD 21205.
Stat Med. 1994;13(19-20):2127-39. doi: 10.1002/sim.4780131920.
Methods are developed to estimate and test for the impact of intervention use on a population's survival function (time to AIDS). Each participant's history is divided into J + 1 components: omega 0 occurring before the intervention is available and omega 1 to omega J occurring later, as the intervention becomes successively more available. Distribution free truncated Kaplan-Meier models based on time since exposure fit separately to the risk sets/outcomes in omega 0 to omega J directly show the changing patterns of survival. Multivariate proportional hazards models can be used to adjust for covariates. Application of these methods indicates that availability of proven anti-AIDS interventions may have delayed time to AIDS by 8 months in an educated HIV-1 infected homosexual cohort with good access to medical care.
