Paper # 587
Strong Association between Medication Possession Ratio and Early Virological Outcomes in Adults on ART in Côte d’Ivoire
E Messou1,2, Marie-Laure Chaix*2,3, D Gabillard1,2, A Minga1,2, E Losina4, T N’Dri-Yoman2, C Danel1,2, C Rouzioux2,3, K Freedberg4, and X Anglaret1,2
1INSERM U897, Univ Bordeaux 2, France; 2Prgm PACCI, Abidjan, Côte d’Ivoire; 3Univ Paris Descartes EA 3620, AP-HP, France; and 4Massachusetts Gen Hosp, Harvard Med Sch, Boston, US
Background: Adherence is a strong determinant of
viral suppression with ART, yet plasma viral load (VL) is not available in many
resource-limited settings. However, medication delivery from the pharmacy can
be easily and accurately measured in settings with computerized prescription
databases. We studied the association between medication possession, virologic
suppression, and viral resistance at 6 and 12 months after ART
initiation in Côte d’Ivoire.
Methods: We
conducted a prospective cohort study in 3 HIV clinics using computerized
monitoring systems. All adults who started ART between February 2006 and
May 2007 had plasma HIV-RNA tests (ANRS real-time PCR technique, threshold for detection
300 copies/mL) and genotypic drug resistance tests if plasma VL was detectable.
The medication possession ratio (MPR) was calculated as the number of days of
ART medications given to the patient at the pharmacy divided by the follow-up
time since ART initiation.
Results: In
this study, 1545 patients started d4T or ZDV+3TC+NVP or EFV, of whom 996
and 941 were alive and followed-up at 6 and 12 months. At 6 months, 197 patients
(19.8%) had detectable VL, of whom 35% had at least one resistance mutation. At
12 months, 232 patients (25%) had detectable VL, of whom 51% had at least one
resistance mutation (leading to resistance to NNRTI 91.5%, to 3TC/FTC 69% and
to ZDV and/or d4T 9.4%). Figure 1 below shows the percentage of patients with
undetectable VL, detectable VL with no resistance, and detectable VL with
resistance at 12 months, stratified by the MPR between the ART starting date
and 12 months. Compared with patients with an MPR >95%, patients with
an MPR of 80-95% and <80% had odds ratios of viral suppression of 2.4 (1.3
to 4.4) and 15.7 (8.7 to 28.3), respectively (P <0.001).
Conclusions: After 12 months of ART, the number of prescriptions filled was
strongly associated with both viral suppression and resistance. Yet, half of
the patients with detectable viral load had no resistance. The medication
possession ratio can be used as a tool for identifying patients who could
benefit from interventions to reinforce adherence.
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