Evaluation of Three Sampling Methods to Monitor Outcomes of Antiretroviral Treatment Programmes in Low- and Middle-Income Countries

Abstract

BackgroundRetention of patients on antiretroviral therapy (ART) over time is a proxy for quality of care and an outcome indicator to monitor ART programs. Using existing databases (Antiretroviral in Lower Income Countries of the International Databases to Evaluate AIDS and Médecins Sans Frontières), we evaluated three sampling approaches to simplify the generation of outcome indicators.Methods and FindingsWe used individual patient data from 27 ART sites and included 27,201 ART-naive adults (≥15 years) who initiated ART in 2005. For each site, we generated two outcome indicators at 12 months, retention on ART and proportion of patients lost to follow-up (LFU), first using all patient data and then within a smaller group of patients selected using three sampling methods (random, systematic and consecutive sampling). For each method and each site, 500 samples were generated, and the average result was compared with the unsampled value. The 95% sampling distribution (SD) was expressed as the 2.5th and 97.5th percentile values from the 500 samples. Overall, retention on ART was 76.5% (range 58.9–88.6) and the proportion of patients LFU, 13.5% (range 0.8–31.9). Estimates of retention from sampling (n = 5696) were 76.5% (SD 75.4–77.7) for random, 76.5% (75.3–77.5) for systematic and 76.0% (74.1–78.2) for the consecutive method. Estimates for the proportion of patients LFU were 13.5% (12.6–14.5), 13.5% (12.6–14.3) and 14.0% (12.5–15.5), respectively. With consecutive sampling, 50% of sites had SD within ±5% of the unsampled site value.ConclusionsOur results suggest that random, systematic or consecutive sampling methods are feasible for monitoring ART indicators at national level. However, sampling may not produce precise estimates in some sites.

Effects of Physical Tracing on Estimates of Loss to Follow-Up, Mortality and Retention in Low and Middle Income Country Antiretroviral Therapy Programs: A Systematic Review

“…A total of 261 papers and 616 conference abstracts were identified by the search strategy and of these 39 studies, 32 papers and 7 conference abstracts, met inclusion criteria[4], [16], [17], [22]–[24], [27], [31]–[62] leading to 54 separate cohorts (47 cohorts in 32 papers, and 7 cohorts in 7 abstracts) available for analysis. In 3 papers, data were available for more than one cohort [17], [56], [57] with 2 of these papers reporting on cohorts with and without physical tracing, [17], [57] while the third paper provided data for 2 cohorts that both performed physical tracing [56].…”

“…In 3 papers, data were available for more than one cohort [17], [56], [57] with 2 of these papers reporting on cohorts with and without physical tracing, [17], [57] while the third paper provided data for 2 cohorts that both performed physical tracing [56]. The 39 included studies reported on 17 countries from sub-Saharan Africa, four multi-country studies from sub-Saharan Africa, three countries from Asia and one from Latin America.…”

“…Note that 7 cohorts [17], [32], [36], [48], [52], [62] reported phone only tracing was available to a proportion of the study population, and 4 cohorts [34], [47], [54], [58] reported physical tracing for a minority of the study population & All ART naïve at baseline unless stated.#Sample size determined via contact with study authors.^Benin, Cote d’Ivoire, Gambia, Mali, Nigeria, Senegal.+Lesotho, Mozambique, Tanzania, Zimbabwe Notes: ART, antiretroviral therapy; WHO, World Health Organization; LTFU, lost to follow up; TF, transfer; NR, not reported; F/U, follow up; NGO, non-governmental organization; NNRTI. Non-nucleoside reverse transcriptase inhibitors; PI, protease inhibitors; NRTI, nucleoside reverse transcriptase inhibitors.…”

“…Furthermore, clinicians, program managers and researchers routinely report on LTFU, mortality and retention to quantify the extent of this issue in LMICs [15]–[17]. Patient tracing may result in the improved classification of unknown outcomes allowing for more accurate estimates of LTFU, mortality, and retention.…”

A three‐tier framework for monitoring antiretroviral therapy in high HIV burden settings

“…However, there is growing concern at the inability of many high-burden countries to report on the outcomes of patients who have been in care for various durations, or even the number of patients in care at a particular point in time [4, 7–10]. In many instances, countries can only report on the number of patients ever initiated on ART.…”