CROI 2016 Abstract eBook

Abstract Listing

Poster Abstracts

9 primary health clinics in KwaZulu-Natal, South Africa. Here we assess whether any compensatory reduction in initiation of sicker patients was seen and whether retention among those newly eligible was satisfactory in this public sector setting. Methods: In this retrospective cohort analysis we compare proportions initiated on ART and RIC at 6 months among pre-ART patients with baseline CD4 taken between July 1 and December 31, 2014 (CD4≤500 cohort) and between July 1 and December 31, 2013 (CD4≤350 cohort). Pregnancy, TB, age <15 years and WHO stage 3 or 4 were exclusion criteria. Outcomes were determined from time of baseline CD4 and analysed using survival analysis. Results: There were 1,932 patients in the CD4≤350 and 1,657 in the CD4≤500 cohorts. In both cohorts median age was 29 years and 71%were female. Mean baseline CD4 counts were 398 (95%CI: 389-410) and 410 (95%CI: 397-422) in the CD4≤350- and CD4≤500 cohorts. Among participants with CD4 351-500, percentage initiated on ART within 3 months increased from 7% to 70% (Table 1); among those with CD4≤200 this increased from 68% to 86%. From baseline CD4 RIC at 6 months was 82% (95%CI: 79%-85%) in the CD4≤500 cohort and 80% (95%CI: 76%-84%) in the CD4≤350 cohort. Conclusions: Expanding eligibility for ART to CD4≤500 resulted in rapid change in time to ART initiation among those with baseline CD4 351-500 without any reduction in initiation among those with a CD4 ≤ 350. This early analysis suggests that staff and patients can effectively implement extended initiation criteria if clinic resources are sufficient; partly achieved in our setting through decongestion using community models of care. ART uptake remained higher in patients with CD4 201-350 than among those with CD4 351-500, indicating room to improve uptake among those initiating with higher CD4 counts as guidelines shift towards test-and-treat. High RIC across time and groups suggests that ‘healthier’ patients do not have increased loss to follow-up. It was possible to implement earlier ART initiation in our high HIV prevalence, low resource-setting without compromising access to care for more vulnerable patients.

1011 The Real-World Impact of CD4-Eligibility Criteria on Retention in HIV Care Jacob Bor 1 ; Matthew P. Fox 2 ; Sydney Rosen 2 ; AtheendarVenkataramani 3 ; FrankTanser 4 ; Deenan Pillay 4 ;Till Bärnighausen 5 1 Boston Univ Sch of PH, Boston, MA, USA; 2 Boston Univ, Boston, MA, USA; 3 Massachusetts General Hosp, Boston, MA, USA; 4 Africa Cntr for Hlth and Pop Studies, Mtubatuba, South Africa; 5 Harvard Sch of PH, Boston, MA, USA Background: Countries are considering whether to offer antiretroviral therapy (ART) to all HIV patients regardless of CD4 count. Clinical trials have found modest health benefits to early ART. However, these trials may underestimate the benefits. By seeking to minimize attrition, they fail to investigate an important behavioral pathway through which deferred ART eligibility may affect health in real world settings: non-retention among patients not yet eligible for therapy. We address this critical gap by assessing the effect of immediate (vs. deferred) ART eligibility on retention in HIV care in rural South Africa. Methods: All patients (n=11,307) presenting to the public sector ART program in Hlabisa sub-district with a first CD4 count between 12 August 2011 and 31 December 2012 were included in the analysis. Patients were eligible for immediate ART if CD4<350 cells/μL; patients not yet eligible for ART were referred to pre-ART care and instructed to return every 6 months for CD4 monitoring. Because of measurement error in the CD4 laboratory assay, assignment to immediate versus deferred ART was effectively random near the threshold. We used a regression discontinuity design to recover causal effects. We assessed the effect of immediate eligibility on retention in HIV care at 12 months, as measured by the presence of a clinic visit, lab test, or ART start date in the interval 6 to 18 months (intent-to-treat effect). In addition, we assessed the causal effect of eligibility on retention in the subgroup of patients whose treatment uptake was determined by their CD4 count (complier causal effects). Results: Immediate eligibility increased 12-month retention from 32% to 50% (intent-to-treat effect: 18% points; 95%CI 11-23; p<0.001) among patients with first CD4 counts close to the 350-cell threshold. Having an eligible CD4 count increased the probability of initiating ART within six months from 18% to 43% (25% points; 95%CI 20-31; p<0.001). In patients whose uptake of ART was determined by the value of their CD4 count, having an eligible CD4 count increased 12-month retention from 21% to 91% (complier effect: 70% points; 95%CI 42-98; p < 0.001). Conclusions: Deferred ART eligibility resulted in dramatically lower retention in HIV care among otherwise similar patients who just missed the cutoff for immediate eligibility. The results suggest that clinical trials may underestimate the benefits of early ART and, consequently, the clinical and population health benefits of eliminating CD4 initiation criteria.

Poster Abstracts

Difference(in(12+month(reten0on:( 18#percentage#points ,(95%CI(11+23(

0 .1 .2 .3 .4 .5 .6 Retention in Care at 12 Months Eligible(for(ART(

Not(eligible(for(ART((by(CD4(count)(

0 100 200 300 400 500 600 700 800 Earliest CD4 Count, cells/uL

Figure. Intent-­‐to-­‐treat effect: ART eligibility at first CD4 count and 12-­‐month retention in care. Due to measurement error in the CD4 laboratory assay, eligibility for ART was as-­‐good-­‐as-­‐ randomly assigned for patients close to the 350-­‐cell threshold. Thus, the difference in retention at the 350-­‐cell threshold can be interpreted as the causal effect of having an eligible CD4 count.

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CROI 2016