Eight International Congress on Drug Therapy in HIV Infection edition:8th location:Glasgow, UK date:12-16 November 2006
Purpose of the Study To determine the diagnostic value of the 2-item Swiss HIV Cohort Study Adherence Questionnaire (SHCS-AQ), (Glass et al., 2006) using virological failure (VF) at 1 year as gold standard.
Methods Using a prospective design, we assessed non adherence (NA) at 3 consecutive time points in 127 HIV+ patients. At T1 (baseline) and T3 (completion) self-reported (SR) NA over the last 4 weeks was assessed by the SHCS-AQ in view of (1) taking adherence (Ta A): How often did you miss a dose of your HIV medication? 6-point scale from never to every day and (2) drug holidays (DH): Did you forget 2 doses one after the other? Yes/no. Diagnostic value of combinations of definitions of SR NA using Ta A (<100%) and DH (1) were explored. At T2 (T1-T3) NA was assessed by electronic monitoring during 3 months. VF was operationalised as a viral load > 400 or 2 consecutive viral loads > 50 copies/ml respectively.
Summary of Results Ten (8%) patients had VF 1 year after completion. Defining SR NA as <100% Ta AH or 1 DH, predicted VF with a sensitivity of only 50% at T1. At T3, sensitivity markedly improved to 90% (Table 1).
Conclusions The 2-item SHCS-AQ predicted VF only moderately at baseline. However, after a second exposure to the SHCS-AQ at T3 and knowing that they were monitored electronically, excellent results were obtained. The effect of this intervention merits further investigation.