Tassie JM, Baijal P, Vitoria MA, et al. Trends in retention on antiretroviral therapy in national programs in low-income and middle-income countries. J Acquir Immune Defic Syndr. 2010 Aug 1;54(4):437-41.
By the end of 2008, an estimated 4,030,000 persons were receiving antiretroviral therapy (ART).(1) Understanding how well patients do on ART is an important indicator of program quality. There are a number of reasons for patients to stop ART, including death, toxicity and loss to follow-up. Loss to follow-up is especially problematic; recent data suggest that a number of these patients have actually died.(2, 3, 4) The United Nations General Assembly Special Session (UNGASS) Declaration of Commitment recommends that the proportion of HIV-infected adults and children known to be remaining on ART at 12, 24, 36 months be adopted as a core indicator.(5) This study examined trends in ART retention up to 48 months after ART initiation in low- and middleincome countries.
To estimate annual patient retention in ART in low- and middle-income countries
National AIDS programs in low- and middle-income countries
This was a cohort study. The outcome variable is the proportion that is still alive and on ART at the time-point analyzed (numerator) divided by the number that started ART during the year in question. That is, the denominator includes patients in the numerator plus those who were known to have died or stopped ART or were lost to follow-up. For reporting in 2008, retention at 12 months was analyzed among patients who started in 2007, retention at 24 months among those who started in 2006 and similarly for longer follow-up. Loss to followup was defined as no contact with a patient within 90 days after the last missed appointment for ART refill. These data were reported by country (both numerators and denominators) to WHO, which then compiled regional and global estimates.
Of the 149 low- and middle-income countries expected to report, 70 (47%) reported 2008 data by March 2009; this represents 32% of patients on ART in 2008. Additionally, 54 (36% or 21% on ART) reported 24-month data, 38 (26% or 11% on ART) reported 36-month data and 30 (20% or 7% on ART) reported 48- month data. Data from 13 of these countries were excluded for a variety of quality reasons. Of 61 countries, 10 (16%) reported a 12-month retention rate greater than 90%, 30 (49%) reported ≥80% and 51 (84%) reported ≥70%. Overall, the median proportion of patients by country retained on ART at 12 months was 80%, at 24 months 74%, at 36 months 70% and at 48 months 72%. Median 12-month retention ranged from 93% in North Africa and the Middle East to 78% in Europe and Central Asia and in sub-Saharan Africa.
The investigators concluded that after a high rate of attrition in the first year of ART, retention on ART stabilizes in subsequent years.
Using the Newcastle-Ottawa scale for cohort studies, this study was of low quality because of the substantial rate of loss to follow-up.
These data need to be viewed with a highly critical eye. Only 47% of low-and middle-income countries, representing only 32% of patients on ART, participated. This raises a substantial probability of selection bias. Given the highly selective nature of which countries participated, these data may represent a best-case scenario for ART retention.
- Mahy H, Tassie J-M, Ghys P, et al. Estimation of ART coverage: methodology and trends. Curr Opin HIV AIDS. 2010;5:97-102.
- Geng EH, Bangsberg DR, Musinguzi N, et al. Understanding reasons for and outcomes of patients lost to follow-up in antiretroviral therapy programs in Africa through a sampling-based approach. J Acquir Immune Defic Syndr. 2010;53:405-11.
- Brinkhof MW, Pujades-Rodriguez M, Egger M. Mortality of patients lost to follow-up in antiretroviral treatment programmes in resource-limited settings: systematic review and meta-analysis. PLoS One. 2009;4:e5790.
- Geng EH, Glidden DV, Emenyonu N, et al. Tracking a sample of patients lost to follow-up has a major impact on understanding determinants of survival in HIV-infected patients on antiretroviral therapy in Africa. Trop Med Int Health. 2010;15 Suppl 1:63-9.
- UNAIDS. Monitoring the Declaration of Commitment on HIV/AIDS-Guidelines on Construction of Core Indicators 2010 Reporting. Geneva, Switzerland: UNAIDS, 2009.