CROI 2015 Program and Abstracts

Abstract Listing

Poster Abstracts

Conclusions: While each day of adherence interruption increases risk of viral rebound, increased duration of prior viral suppression and use of long-half life medication (efavirenz) are protective. This analysis is limited by the small number of interruptions. Re-suppression of most terminated interruptions is promising proof-of-concept support for real-time adherence intervention. 557 Determinants of Adherence to Antiretroviral Therapy Differ Between Africa and Asia Rimke Bijker 1 ; Awachana Jiamsakul 2 ; Margaret Siwale 3 ; Sasisopin Kiertiburanakul 4 ; Cissy M. Kityo 5 ; Praphan Phanuphak 6 ;Tobias F. Rinke deWit 1 ; OonTek Ng 7 ; Raph L. Hamers 1 ; PASER-TASER Cohort Collaboration 1 PASER-TASER Cohort Collaboration 1 Amsterdam Institute for Global Health and Development, Amsterdam, Netherlands; 2 The Kirby Institute, Sydney, Australia; 3 Lusaka Trust Hospital, Lusaka, Zambia; 4 Ramathibodi Hospital, Mahidol University, Bangkok, Thailand; 5 Joint Clinical Research Centre, Kampala, Uganda; 6 HIV-NAT/Thai Red Cross AIDS Research Centre, Bangkok, Thailand; 7 Tan Tock Seng Hospital, Novena, Singapore Background: Adherence to antiretroviral therapy (ART) has been poorly studied among HIV-infected populations in resource-limited settings. We studied determinants of adherence in sub-Saharan Africa and Asia. Methods: In a cohort collaboration in Africa (6 countries, 13 sites) and Asia (5 countries, 11 sites) adherence was assessed using the WHO-validated Adherence Visual Analogue Scale (VAS) at each clinic visit, during the first 24 (all sites) or 36 (15 sites) months of 1st-line ART. The main outcome was suboptimal mean adherence (SubAdh), defined as mean VAS<95% for each 6-month period. We used generalized estimating equations multivariable regression, adjusting for number of adherence assessments, site type and calendar year. Region-of-residence was assessed as a potential effect modifier. Results: In the first 24 months of follow-up, 23,074 VAS assessments were performed in 3,913 participants; median per participant was 7 (IQR 6-8) in Africa (n=2,409) and 8 (IQR 5-9) in Asia (n=1,504). Of 12,889 mean adherence scores, 6.5% (832/12,889) were classified as SubAdh, with 7.3% (614/8,398) in Africa versus 4.9% (218/4491) in Asia (Chi2, p<0.001) ( Figure ). SubAdh was strongly associated with virological failure ( ≥ 400 c/mL) at month 12 and 24 (Chi2, p<0.001). In Africa (but not in Asia), factors associated with SubAdh were male sex (OR 1.4, 95%CI 1.1-1.6) and any concomitant medication (1.9, 1.2-3.1); attending a non-government facility (0.7, 0.5-0.9) and older age were associated with less SubAdh. In Asia, relative to heterosexuals, SubAdh was lower in men who have sex with men (0.5, 0.3-0.9) and higher in injecting drug users (3.5, 2.1-5.8). In both regions, longer ART duration (extending to at least 36 months) was associated with better adherence. A sensitivity analysis that accounted for attrition, using last observation carried forward methods, suggested that adherence improvement with ART duration was not entirely due to attrition bias or missing data. Type of ART regimen was not associated with SubAdh. Participants from high or upper-middle income countries had a 24% (95%CI 7-38%) reduced risk of SubAdh, compared to low or lower-middle income countries (p=0.007).

Poster Abstracts

Figure. Suboptimal adherence over time across regions in participants who initiated first-line ART (n=3913) Conclusions: Cross-regional differences may be partly related to health system resources, although social desirability bias cannot be excluded. Interventions to improve adherence need to be locally tailored and should particularly target the first ART years. 558 Retention on Antiretroviral Therapy by Sex and Pregnancy Status in a Large Cohort of HIV-Infected Patients in Rural Nigeria Usman I. Gebi 2 ; Meridith Blevins 1 ; MukhtarY. Muhammad 2 ; C.WilliamWester 1 ; Muktar H. Aliyu 1 1 Vanderbilt University, Nashville, TN, US; 2 Friends for Global Health Initiative Nigeria, Abuja, Nigeria Background: To examine whether differences exist in retention on antiretroviral therapy (ART) by sex and pregnancy status in a cohort of HIV-infected patients enrolled in a HIV treatment program in rural north-central Nigeria. Methods: We used routine program data collected from June 2009–September 2013. The study population included HIV-infected ART-naïve patients entering care and treatment (age ≥ 15 years). Kaplan-Meier and cumulative incidence estimates were calculated for early ART initiation and loss-to-follow up (LTFU) by sex and pregnancy status. Results: and loss-to-follow up (LTFU) by sex and pregnancy status. A total of 3,813 ART-naïve clients (68%women, 11% of whomwere pregnant) were enrolled into care during the study period. The median CD4+ cell count for all clients was 232 cells/ m L [interquartile range (IQR): 114-390]; 29% of clients had advanced disease (WHO clinical stage 3/4). Pregnant women had higher median CD4+ cell counts (306 cells/ m L [IQR: 174-475] than non-pregnant women (244 cells/ m L [IQR: 121-415]), and men (197 cells/ m L [IQR: 91-328]), p<0.001. The proportion of pregnant clients initiating ART within 90 days of enrollment (78%, n=213) was significantly higher than the corresponding proportion of non-pregnant women (54%, n=1261) and men (53%, n=650), p<0.001. Pregnant women initiated ART twice as fast as non-pregnant women and men (median [IQR] days from enrollment to ART initiation for pregnant women = 7 days [0-21] vs. 14 days [7-49] for non-pregnant women and 14 days [7-42] for men). No significant difference was observed between the groups in cumulative incidence of LTFU during the first 12 months following ART initiation (66% of pregnant women vs. 65% of non-pregnant women and 67% of men), p=0.79.

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CROI 2015