Because considerable information about progression of human immunodeficiency virus (HIV) infection has been provided by studies of cohorts of individuals with prevalent HIV infection, this study was designed to investigate bias due to onset confounding (differential time-since-infection distributions) and differential length-biased sampling in epidemiologic analyses of data from such cohorts.
Subjects were participants in the Italian Seroconverters Study, a seroincident cohort of more than 1,200 adults seen at ambulatory care clinics in Italy, with observed HIV seroconversion in 1980-1988.
Acquired immunodeficiency syndrome (AIDS) diagnoses, based on the 1987 Centers for Disease Control case definition, and mortality were ascertained through Italian national registries through 1994.
To estimate bias in prevalent cohorts, a series of pseudoseroprevalent (PSP) cohorts were drawn by sampling, from among the total seroincident cohort, prevalent AIDS-free subjects in each calendar year.
The relative AIDS risk associated with a given covariate was calculated in each PSP cohort and compared with the relative AIDS risk for that covariate in the seroincident cohort.
Relative risks were estimated by both the ratio of AIDS incidence densities and the relative AIDS hazards from proportional hazards regression. (...)
Mots-clés Pascal : SIDA, Virose, Infection, Virus immunodéficience humaine, Lentivirinae, Retroviridae, Virus, Prévalence, Incidence, Evolution, Epidémiologie, Méthodologie, Biais méthodologique, Homme, Etude cohorte, Immunopathologie, Immunodéficit
Mots-clés Pascal anglais : AIDS, Viral disease, Infection, Human immunodeficiency virus, Lentivirinae, Retroviridae, Virus, Prevalence, Incidence, Evolution, Epidemiology, Methodology, Methodological bias, Human, Cohort study, Immunopathology, Immune deficiency
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 97-0534158
Code Inist : 002B06D01. Création : 13/02/1998.