Abstract

There is presently no validated objective method available to measure participants' sexual behaviour or adherence to study product use in HIV prevention trials. Because of this challenge there has been an indeterminate amount of product non-adherence that has precluded the accurate measurement of the safety and efficacy of novel biomedical interventions. Measurement has historically relied on self-report, which suffers from several biases, including recall and social desirability. To address these, researchers have use alternative interview modes (ACASI) and technologies (cell phones/SMS) with varying success. Pros and cons of other innovative approaches to measure adherence will be discussed, including use of indirect objective measures of adherence (eg, events monitoring systems, mucin tests of gel applicators), real time electronic measures, biomarkers and Directly Monitored Adherence Methods. Each of these approaches has strengths and limitations, thereby precluding any of them from serving as a universal “gold standard”. Discussion will include what can and should be measured “objectively” as well as lessons learnt for future biomedical prevention trials.