Monthly Unannounced Pill Counts for Monitoring HIV Treatment Adherence: Tests for Self-Monitoring and Reactivity Effects

Abstract

Background: Unannounced home-based pill counts conducted in person or on the telephone are reliable and valid for monitoring medication adherence. However, expecting to have one’s pills counted, organizing medications for pill counts, and increased attention from the person conducting the pill counts may have reactive effects and inadvertently improve adherence. The current study determined whether monthly unannounced pill counts conducted by telephone influence adherence over time. Methods: Two prospective cohorts, one drawn from a social support condition in a behavioral intervention trial (n=186) and the other an observational study (n=187), were followed for 12 months and 8 months, respectively. Medication adherence was monitored using monthly unannounced pill counts conducted by telephone. In addition, blood plasma viral load was collected at the final pill count for the observational cohort. Results: Analyses did not indicate increases in medication adherence over time for antiretroviral or psychiatric medications among men, women, people with detectable and undetectable viral loads, and various medication regimens. Conclusions: Unannounced pill counts conducted by telephone do not demonstrate reactivity effects and remain a viable, unobtrusive, objective method of monitoring medication adherence.