Reliability of self-reported sexual and safe sex behavior among heterosexual HIV discordant couples was assessed by matching individual responses of couples to a common set of questions and validated by matching with pregnancy and seroconversion during study period. Demographic, clinical and sexual behavior information was collected individually from 457 consenting married discordant couples using structured questionnaires at screening, enrollment and at four quarterly visits. Reliability of self-reports tested using Kappa statistics. At screening, level of agreement about spouse being regular partner (Kappa = 0.96) and having had sexual intercourse with spouse in the last quarter (Kappa = 0.84) was noted. Moderate agreement observed about frequency of condom use (Kappa = 0.639) and condom tear (Kappa = 0.428). Agreement on reporting sexual contacts with spouse and consistent condom use increased (P < 0.001) over follow-ups. Four of 6 couples that seroconverted reported using condoms consistently, and 2 of these seroconverted. Couple histories of all 11 sero-discordant couples reporting pregnancy matched, of these 8 couples reported use of condoms and only 3 couples reported non-use of condoms during the preceding period. Sensitive sexual information can be collected using self-reports but it should be used with caution. Involving couples and using biological parameters concurrently may enhance validity of self-reports.
Keywords: Concordance; HIV discordant couples; reliability; self-reports; sexual behavior.