Introduction: Face-to-face (FTF) interviews are the most frequently used means of obtaining information on sexual and drug injecting behaviours from men who have sex with men (MSM) and men who inject drugs (MWID). However, accurate information on these behaviours may be difficult to elicit because of sociocultural hostility towards these populations and the criminalization associated with these behaviours. Audio computer assisted self-interview (ACASI) is an interviewing technique that may mitigate social desirability bias in this context.
Methods: This study evaluated differences in the reporting of HIV-related risky behaviours by MSM and MWID using ACASI and FTF interviews. Between August and September 2010, 712 MSM and 328 MWID in Nigeria were randomized to either ACASI or FTF interview for completion of a behavioural survey that included questions on sensitive sexual and injecting risk behaviours. Data were analyzed separately for MSM and MWID. Logistic regression was run for each behaviour as a dependent variable to determine differences in reporting methods.
Results: MSM interviewed via ACASI reported significantly higher risky behaviours with both women (multiple female sexual partners 51% vs. 43%, p = 0.04; had unprotected anal sex with women 72% vs. 57%, p = 0.05) and men (multiple male sex partners 70% vs. 54%, p≤0.001) than through FTF. Additionally, they were more likely to self-identify as homosexual (AOR: 3.3, 95%CI:2.4-4.6) and report drug use in the past 12 months (AOR:40.0, 95%CI: 9.6-166.0). MWID interviewed with ACASI were more likely to report needle sharing (AOR:3.3, 95%CI:1.2-8.9) and re-use (AOR:2.2, 95%CI:1.2-3.9) in the past month and prior HIV testing (AOR:1.6, 95%CI 1.02-2.5).
Conclusion: The feasibility of using ACASI in studies and clinics targeting key populations in Nigeria must be explored to increase the likelihood of obtaining more accurate data on high risk behaviours to inform improved risk reduction strategies that reduce HIV transmission.