Extending visit intervals for clinically stable patients on antiretroviral therapy: multicohort analysis of HIV programs in Southern Africa

BACKGROUND The World Health Organization recommends differentiated antiretroviral therapy (ART) delivery with longer visit intervals for clinically stable patients. We examined time trends in visit frequency and associations between criteria for clinical stability and visit frequency in ART programs in Southern Africa. METHODS We included adults on ART from 4 programs with viral-load monitoring, 2 programs with CD4 monitoring, and 4 programs with clinical monitoring of ART. We classified patients as clinically stable based on virological (viral load 200 cells/µL), or clinical (no current tuberculosis) criteria. We used Poisson regression and survival models to examine associations between criteria for clinical stability and the rate of clinic visits. RESULTS We included 180,837 patients. There were trends toward fewer visits in more recent years and with longer ART duration. In all ART programs, clinically stable patients were seen less frequently than patients receiving failing ART, but the strength of the association varied. Adjusted incidence rate ratios comparing visit rates for stable patients with patients on failing ART were 0.82 (95% confidence interval: 0.73 to 0.90) for patients classified based on the virological criterion, 0.81 (0.69 to 0.93) for patients classified based on the clinical criterion, and 0.90 (0.85 to 0.96) for patients classified based on the immunological criterion for stability. CONCLUSION Differences in visit rates between stable patients and patients failing ART were variable and modest overall. Larger differences were seen in programs using virological criteria for clinical stability than in programs using immunological criteria. Greater access to routine viral-load monitoring may increase scale-up of differentiated ART delivery.