Patient Retention in Antiretroviral Therapy Programs in Sub-Saharan Africa: A Systematic Review

Background: Long-term retention of patients in Africa's rapidly expanding antiretroviral therapy (ART) programs for HIV/AIDS is essential for these programs' success but has received relatively little attention. In this paper we present a systematic review of patient retention in ART programs in sub-Saharan Africa. Methods and Findings: We searched Medline, other literature databases, conference abstracts, publications archives, and the “gray literature” (project reports available online) between 2000 and 2007 for reports on the proportion of adult patients retained (i.e., remaining in care and on ART) after 6 mo or longer in sub-Saharan African, non-research ART programs, with and without donor support. Estimated retention rates at 6, 12, and 24 mo were calculated and plotted for each program. Retention was also estimated using Kaplan-Meier curves. In sensitivity analyses we considered best-case, worst-case, and midpoint scenarios for retention at 2 y; the best-case scenario assumed no further attrition beyond that reported, while the worst-case scenario assumed that attrition would continue in a linear fashion. We reviewed 32 publications reporting on 33 patient cohorts (74,192 patients, 13 countries). For all studies, the weighted average follow-up period reported was 9.9 mo, after which 77.5% of patients were retained. Loss to follow-up and death accounted for 56% and 40% of attrition, respectively. Weighted mean retention rates as reported were 79.1%, 75.0% and 61.6 % at 6, 12, and 24 mo, respectively. Of those reporting 24 mo of follow-up, the best program retained 85% of patients and the worst retained 46%. Attrition was higher in studies with shorter reporting periods, leading to monthly weighted mean attrition rates of 3.3%/mo, 1.9%/mo, and 1.6%/month for studies reporting to 6, 12, and 24 months, respectively, and suggesting that overall patient retention may be overestimated in the published reports. In sensitivity analyses, estimated retention rates ranged from 24% in the worse case to 77% in the best case at the end of 2 y, with a plausible midpoint scenario of 50%. Conclusions: Since the inception of large-scale ART access early in this decade, ART programs in Africa have retained about 60% of their patients at the end of 2 y. Loss to follow-up is the major cause of attrition, followed by death. Better patient tracing procedures, better understanding of loss to follow-up, and earlier initiation of ART to reduce mortality are needed if retention is to be improved. Retention varies widely across programs, and programs that have achieved higher retention rates can serve as models for future improvements. Almost half of people entering African HIV treatment programs were lost to follow-up or died within two years, according to this systematic review by Sydney Rosen and colleagues. Background.: About 25 million people in sub-Saharan Africa are infected with the human immunodeficiency virus (HIV), the cause of acquired immunodeficiency syndrome (AIDS). Every year, about three million more people become infected with HIV and 2 million die from AIDS in this region, where the pandemic has reduced life expectancy, orphaned many children, and reversed economic growth. Since 1996, HIV-positive people living in wealthier parts of the world have had access to cocktails of antiretroviral drugs that hold HIV in check and allow them to live relatively normal, healthy lives. But these drugs are expensive and it is only in the past five years that antiretroviral therapy (ART) programs have been initiated in sub-Saharan Africa, often with international support. Why Was This Study Done?: For ART to work, HIV-infected individuals whose immune systems have been damaged by the virus have to take antiretroviral drugs regularly for the rest of their lives. If people take ART irregularly or stop taking their medications they may become sicker or die, or the viruses they carry may become resistant to antiretroviral drugs. Several studies have looked at how well patients on ART stick to their day-to-day medication schedules, but how long patients stay in treatment programs, which they must do to prevent illness and death from AIDS, has received little attention. In this study the researchers reviewed reports of whether patients stay in treatment in ART programs in sub-Saharan Africa, and also looked at the reasons why they drop out. What Did the Researchers Do and Find?: The researchers identified 32 scientific reports published or presented at meetings between 2000 and 2007 that gave details of the proportion of adult patients retained (alive and receiving ART) in ART treatment programs (not including research studies) in 13 countries in sub-Saharan Africa. The average follow-up time of the programs (adjusted for number of patients in each) was 9.9 months. At this time, 77.5% of the patients were retained on average. Of the patients not retained, just under half had died and half had been lost to follow up. That is, they had missed clinic visits or had not picked up their medication. Estimated average retention rates at 6, 12, and 24 months were 79.08%, 75% and 61.6%, respectively; retention rates reported at 24 months ranged between 46% and 85% of patients. Finally, using sensitivity analysis (a technique that can estimate best- and worst-case possibilities), the researchers estimated that actual retention in ART programs after 2 years probably lies between one-quarter and three-quarters of patients. What Do These Findings Mean?: These results show that roughly half of people starting HIV treatment programs in Africa are no longer receiving treatment after two years. The overall success rates of African treatment programs may actually be even lower, if one takes into account that programs with very low retention may be unlikely to publish their results. This study therefore indicates that a worrying number of patients in sub-Saharan Africa who need ART are lost from treatment programs. Because many of these patients are lost because they die from AIDS, one way to improve retention might be to start treating people with ART earlier, before they become seriously ill from HIV. Better efforts to find out exactly why patients drop out of programs (for example, the cost of drugs and/or of transport to clinics) might reduce the number of patients lost to follow up. The researchers also suggest that ART programs with very high retention rates might serve as models to improve retention rates in other programs. Additional Information.: Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0040298.