Audio computer-assisted survey instrument versus face-to-face interviews: optimal method for detecting high-risk behaviour in pregnant women and their sexual partners in the south of Brazil.

Audio computer-assisted survey instrument (ACASI) has been shown to decrease under-reporting of socially undesirable behaviours, but has not been evaluated in pregnant women at risk of HIV acquisition in Brazil. We assigned HIV-negative pregnant women receiving routine antenatal care at in Porto Alegre, Brazil and their partners to receive a survey regarding high-risk sexual behaviours and drug use via ACASI (n = 372) or face-to-face (FTF) (n = 283) interviews. Logistic regression showed that compared with FTF, pregnant women interviewed via ACASI were significantly more likely to self-report themselves as single (14% versus 6%), having >5 sexual partners (35% versus 29%), having oral sex (42% versus 35%), using intravenous drugs (5% versus 0), smoking cigarettes (23% versus 16%), drinking alcohol (13% versus 8%) and using condoms during pregnancy (32% versus 17%). Therefore, ACASI may be a useful method in assessing risk behaviours in pregnant women, especially in relation to drug and alcohol use.