Toward an information–motivation–behavioral skills model of microbicide adherence in clinical trials

Abstract

Unless optimal adherence in microbicide clinical trials is ensured, an efficacious microbicide may be rejected after trial completion, or development of a promising microbicide may be stopped, because low adherence rates create the illusion of poor efficacy. We provide a framework with which to conceptualize and improve microbicide adherence in clinical trials, supported by a critical review of the empirical literature. The information–motivation–behavioral skills (IMB) model of microbicide adherence conceptualizes microbicide adherence in clinical trials and highlights factors that can be addressed in behavioral interventions to increase adherence in such trials. This model asserts that microbicide adherence-related information, motivation, and behavioral skills are fundamental determinants of adherent microbicide utilization. Specifically, information consists of objective facts about microbicide use (e.g., administration and dosage) as well as heuristics that facilitate use (e.g., microbicides must be used with all partners). Motivation to adhere consists of attitudes toward personal use of microbicides (e.g., evaluating the consequences of using microbicides as good or pleasant) as well as social norms that support their use (e.g., beliefs that a sexual partner approves use of microbicides). Behavioral skills consist of objective skills necessary for microbicide adherence (e.g., the ability to apply the microbicide correctly and consistently). Empirical evidence concerning microbicide acceptability and adherence to spermicides, medication, and condom use regimens support the utility of this model for understanding and promoting microbicide adherence in clinical trials.

Keywords:

• microbicides
• adherence
• clinical trials
• HIV prevention
• health behavior change models

Acknowledgements

Special thanks to K. Rivet Amico, Deborah Cornman, Leila Mansoor, and Quarraisha Abdool Karim in their feedback on the model presented in this paper.

Notes

1. To date, no microbicide has been proven effective in clinical trials, and a few trials have been stopped due to trial feasibility concerns, ineffectiveness, or potential harm (e.g., Microbicides Development Programme, 2008; van de Wijgert & Shattock, 2007).

2. Note that for ethical reasons, condom adherence is emphasized in clinical trials as well, and tests of microbicide efficacy rely on measures of averting residual risk, or risk of HIV infection even when a condom is used (Alliance for Microbicide Development, 2009).

3. Many microbicide candidates currently in various clinical trials and active preclinical development actually are ARV medications (Alliance for Microbicide Development, 2009), further demonstrating the connection between ARV medication adherence and microbicide adherence in clinical trials.