Association between condom use and HIV infection: a randomised study of self reported condom use measures

Study objective-To compare the association between different measures of co ndom use and prevalent HIV infection. Design-Randomised cross sectional study to assess association between HIV i nfection and different measures of self reported condom use. Female sex wor kers were randomised to one of five different face to face questionnaires o n condom use. Three questionnaires used always to never scales to measure u se but differed in the reference period for use; a fourth asked about use i n the last 10 coital acts; and the fifth was a retrospective log of coital acts in the past two weeks. Use was assessed with new clients, repeat clien ts, and non-clients. Setting-Yaounde and Douala, Cameroon. Participants-2266 female sex workers. Main results-The association between condom use and prevalent HIV infection varied for different measures of condom use. None of the five level measur es showed a dose response protective effect of condom use. Measures aimed a t reducing recall bias (measures based on the past 10 coital acts or a coit al log) showed little or no association with prevalent infection. Measures based on the past month or six months had a stronger association with preva lent infection. Regardless of the type of measure or reference period, the strongest association between use and infection was for use with partners w ho were not clients. C onclusion-These findings underscore challenges described by others of measu ring condom use and interpreting the association between use and prevalent infection.