Original Paper

AIDS and Behavior

, Volume 15, Issue 2, pp 407-421

First online:

Assessing the Reporting of Adherence and Sexual Activity in a Simulated Microbicide Trial in South Africa: An Interview Mode Experiment Using a Placebo Gel

  • Barbara S. MenschAffiliated withPopulation Council Email author 
  • , Paul C. HewettAffiliated withPopulation Council
  • , Sharon AbbottAffiliated withPopulation Council
  • , Johanna RankinAffiliated withPopulation Council
  • , Sarah LittlefieldAffiliated withPopulation Council
  • , Khatija AhmedAffiliated withSetshaba Research Centre, University of Limpopo/Medunsa Campus
  • , Nazira CassimAffiliated withSetshaba Research Centre, University of Limpopo/Medunsa Campus
  • , Smruti PatelAffiliated withEmpilisweni Centre for Wellness Studies, University of Cape Town
  • , Gita RamjeeAffiliated withIsipingo Clinic, Medical Research Council
    • , Thesla PalaneeAffiliated withReproductive Health and HIV Research Unit, Tshireletso Wellness Centre, Chris Hani Baragwanath Hospital
    • , Stan MierzwaAffiliated withPopulation Council
    • , Stephanie Skoler-KarpoffAffiliated withMemorial Sloan Kettering Cancer Center

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Misreporting of adherence undermines detection of an association between product use and HIV infection in microbicide trials. This study investigates whether, in a placebo trial, audio computer-assisted self-interviewing (ACASI) produces more accurate reporting of adherence and sexual behavior than a face-to-face interview (FTFI). At three South African clinics, 849 women were enrolled and instructed to use applicators filled with placebo gel; participants were randomly assigned to FTFI or ACASI. Behavioral reports were validated through two biomarkers that detect product usage and unprotected sex. For most behaviors, ACASI generated significantly higher reporting, although differences by interview mode appeared to diminish over time. ACASI participants were more likely to report having had sex without gel, but reported and tested applicators did not indicate greater honesty about gel insertion with ACASI. While comparisons of reported unprotected sex with the validated biomarker revealed more agreement with ACASI than with FTFI, differences were small.


ACASI Adherence Biomarkers Microbicides Sexual activity