Exploring definitions of retention in care for people living with HIV in the United States in the modern treatment era.

Objective: To describe retention in HIV care based on various definitions of retention in the modern treatment era.

Design: A cohort study of people enrolled in care at seven mostly urban HIV clinics across the United States, 2010-2018.

Methods: We estimated retention based on missed visits, kept visits, kept encounters (clinical visits, CD4 counts, and viral loads), and HIV labs. We contrasted risk factors for retention by different definitions and estimated odds ratios for of viral suppression and hazard ratios for mortality in 2 years immediately following the year in which retention was defined (the study year).

Results: Across 108 171 person-years (N = 21 481 people), in 71% of years people kept ≥75% of scheduled visits; in 78%, people kept ≥2 visits >90 days apart; in 74%, people had ≥2 HIV labs >90 days apart; and in 47%, people had no gaps >6 months in clinic visits. Missing >25% of scheduled visits despite attending ≥2 visits >90 days apart was associated with nonwhite non-Hispanic race/ethnicity, history of injection drug use, and prior AIDS diagnosis. In contrast, attending ≥75% of scheduled visits while not attending ≥2 visits >90 days apart was associated with male sex, white race, no injection drug use history, and no prior AIDS diagnosis. Subsequent viral nonsuppression was more strongly associated with missed- than kept-visit measures of retention; 2-year mortality was only associated with failure to be retained by missed-visit measures.

Discussion: Missed and kept-visit definitions of retention capture different constructs. Missed-visit measures are more strongly associated with poor HIV outcomes.