Comparison of sexual behaviour data collected using a coital diary and a clinic based interview during a Microbicide pilot study in Mwanza, Tanzania


Shelley Lees, Claire Cook, Andrew Vallely, Nicola Desmond, Caroline Allen, Kagemlo Kiro, Joyce Wamoyi, Lemmy Medard, Robert Pool, Richard J Hayes, David A Ross



The performance of coital diaries and clinic-based interviews to measure sexual behaviour were compared during a pilot study for a Phase III microbicide trial.


In Mwanza 59 women were enrolled for 4 weeks and provided with 20 placebo gels. Weekly, women were given coital diaries (CD) to complete daily. At the final clinic visit, women attended a face-to-face interview (Clinic FFI) about their sexual behaviour, and gel use was accounted for (GA). Comparisons were made of CD, Clinic FFI and GA data. In-depth interviews following clinic visits elicited reasons for discrepancies in reports.


Twice as many sex acts during one week were recorded in the CD (median 4) compared with the clinic FFI (median 2). At the clinic FFI more women reported using the gel for each sex act (84% v. 40%; p<0.001) and vaginal washing for each sex act (98% v. 56%; p<0.001) compared with the CD. Over four weeks 16.4% of women recorded sex during menstruation in CDs compared with 1.8% at the clinic visit (p=0.01). The median number of gels used reported in the CDs was the same as the GA (10) with 59% agreement on the number used within +/−2 gels. Reasons for misreporting during clinic FFI were reported to have been poor recall, embarrassment or misunderstanding. Inaccuracies in CDs were attributed to misunderstanding or poor recording.


CDs elicited higher recording of sex acts and lower reporting of gel use than clinic FFIs which has implications for measuring adherence during clinical trials. With clear instructions and support, coital dairies should be considered in future microbicide trial design.


Sexually Transmitted Diseases