title: Differences between seven measures of self-reported numbers of clients of female sex workers in southern India: implications for individual- and population-level analysis.
abstract: Quantifying sexual activity of sub-populations with high-risk sexual behaviour is important in understanding HIV epidemiology. This study examined inconsistency of seven outcomes measuring self-reported clients per month (CPM) of female sex workers (FSWs) in southern India and implications for individual/population-level analysis. Multivariate negative binomial regression was used to compare key social/environmental factors associated with each outcome. A transmission dynamics model was used to assess the impact of differences between outcomes on population-level FSW/client HIV prevalence. Outcomes based on 'clients per last working day' produced lower estimates than those based on 'clients per typical day'. Although the outcomes were strongly correlated, their averages differed by approximately two-fold (range 39.0-79.1 CPM). The CPM measure chosen did not greatly influence standard epidemiological 'risk factor' analysis. Differences across outcomes influenced HIV prevalence predictions. Due to this uncertainty, we recommend basing population-based estimates on the range of outcomes, particularly when assessing the impact of interventions.
authors.affiliation: Division of AIDS, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, Canada. kdeering@cfenet.ubc.ca
authors.forename: Kathleen N
authors.initials: KN
authors.lastname: Deering
authors.forename: P
authors.initials: P
authors.lastname: Vickerman
authors.forename: M
authors.initials: M
authors.lastname: Pickles
authors.forename: S
authors.initials: S
authors.lastname: Moses
authors.forename: J F
authors.initials: JF
authors.lastname: Blanchard
authors.forename: B M
authors.initials: BM
authors.lastname: Ramesh
authors.forename: S
authors.initials: S
authors.lastname: Isac
authors.forename: M-C
authors.initials: MC
authors.lastname: Boily
mesh_terms: D000328:Adult; D000465:Algorithms; D015982:Bias; D017280:Condoms / Q000706:statistics & numerical data*; D003430:Cross-Sectional Studies; D005260:Female; D015658:HIV Infections / Q000453:epidemiology / Q000517:prevention & control*; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D007194:India / Q000453:epidemiology; D010342:Patient Acceptance of Health Care / Q000706:statistics & numerical data; D015995:Prevalence; D015203:Reproducibility of Results; D012189:Retrospective Studies; D057566:Self Report; D060386:Sex Workers / Q000706:statistics & numerical data*; D012725:Sexual Behavior / Q000706:statistics & numerical data*; D012747:Sexual Partners