Multiple self-report measures of antiretroviral adherence correlated in Sierra Leone, but did they agree?

In resource-poor settings, studies validating multiple self-report measures of adherence are limited and do not include data from West Africa. We prospectively assessed the associations between multiple self-report measures of adherence in 58 patients receiving antiretroviral therapy. Self-report measures included a 30-day visual analog scale, 30-day qualitative single-item measure, Adult AIDS Clinical Trial Group 4-day recall, and 3-level categorical 7-day qualitative measure. Unannounced pill count was the objective measure. Spearman's rho correlation coefficients, Bland-Altman plots, and receiver operator curve analyses were performed. Median and mean adherence by pill count were 81.8% and 78.6%, respectively. All self-report measures had either intermediate or high correlation with the pill count, and the 7-day measure had the highest level of correlation with pill count (r = 0.72). All self-report measures demonstrated good agreement when mean pill count adherence was greater than 90%. All but the 7-day measure posed challenges to patient understanding and administration of the measure. In this sample of participants that displayed largely suboptimal adherence, the 7-day measure was preferable, but all self-report measures demonstrated relatively good agreement with the objective criterion pill count measure and are adequate for clinical use in settings such as Sierra Leone.