Polling booth surveys: a novel approach for reducing social desirability bias in HIV-related behavioural surveys in resource-poor settings.

This study compared rates of HIV-related sexual risk behaviours reported in individual face-to-face (FTFI) and group anonymous polling booth (PBS) interviews in India. In PBS, respondents grouped by gender and marital status answered yes/no questions by putting tokens with question numbers in colour-coded containers. Data were subsequently collated for each group as a whole, so responses were not traceable back to individuals. Male and female PBS participants reported substantially higher rates of pre-marital, extra-marital, commercial and anal sex than FTFI participants; e.g. 11 vs. 2% married males reported paying for sex; 6 vs. 1% unmarried males reported homosexual anal sex.