LAUSR

Recall and social desirability bias undermine self-report of paper-and-pencil questionnaires. Mobile phone questionnaires may overcome these challenges. We assessed and compared sexual risk behavior reporting via in-clinic paper-and-pencil and mobile phone questionnaires. HVTN 915 was a prospective cohort study of 50 adult women in Soweto, who completed daily mobile phone, and eight interviewer-administered in-clinic questionnaires over 12 weeks to assess sexual risk. Daily mobile phone response rates were 82% (n = 3486/4500); 45% (n = 1565/3486) reported vaginal sex (median sex acts 2 (IQR: 1–3)) within 24 h and 40% (n = 618/1565) consistent condom. Vaginal sex reporting was significantly higher via mobile phone across all visits (p < 0.0001). There was no significant difference in condom use reporting by mobile phone and in-clinic paper-based questionnaires across all visits (p = 0.5134). The results show high adherence and reporting of sex on the mobile phone questionnaire. We demonstrate feasibility in collecting mobile phone sexual risk data.