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The effect of covariates on the induction time of AIDS using improved imputation of exact seroconversion times
Author(s) -
Gauvreau Kimberlee,
Degruttola Victor,
Pagano Marcello,
Bellocco Rino
Publication year - 1994
Publication title -
statistics in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.996
H-Index - 183
eISSN - 1097-0258
pISSN - 0277-6715
DOI - 10.1002/sim.4780131912
Subject(s) - covariate , imputation (statistics) , seroconversion , statistics , medicine , econometrics , computer science , missing data , mathematics , human immunodeficiency virus (hiv) , virology
This paper explores the effects of covariates such as age, gender, chronological time of seroconversion, and mode of virus transmission on the interval between HIV seroconversion and the development of AIDS. For many cohorts which are available to provide information about such effects, both the time of seroconversion and the time of onset of AIDS may be right‐ or interval‐censored. To analyse these doubly‐censored data, we propose a method in which we first estimate the marginal distribution of the chronological time of seroconversion and use this distribution to impute the seroconversion time for each subject. Subsequently, we estimate the distribution of induction times conditional on the seroconversion distribution. We apply this technique to a cohort of HIV seropositive subjects recruited from various outpatient facilities throughout Italy and show that age at seroconversion has the greatest effect on induction time.