Objective: To assess associations between engagement in-care and future mortality.
Design: UK-based observational cohort study.
Methods: HIV-positive participants with more than one visit after 1 January 2000 were identified. Each person-month was classified as being in or out-of-care based on the dates of the expected and observed next care visits. Cox models investigated associations between mortality and the cumulative proportion of months spent in-care (% IC, lagged by 1 year), and cumulative %IC prior to antiretroviral therapy (ART) in those attending clinic for more than 1 year, with adjustment for age, CD4/viral load, year, sex, infection mode, ethnicity, and receipt/type of ART.
Results: The 44 432 individuals (27.8% women; 50.5% homosexual, 28.9% black African; median age 36 years) were followed for a median of 5.5 years, over which time 2279 (5.1%) people died. Higher %IC was associated with lower mortality both before [relative hazard 0.91 (95% confidence interval 0.88-0.95)/10% higher, P = 0.0001] and after [0.90 (0.87-0.93), P = 0.0001] adjustment. Adjustment for future CD4 changes revealed that the association was explained by poorer CD4 cell counts in those with lower %IC. In total 8730 participants under follow-up for more than 1 year initiated ART of whom 237 (2.7%) died. Higher values of %IC prior to ART initiation were associated with a reduced risk of mortality before [0.29 (0.17-0.47)/10%, P = 0.0001] and after [0.36 (0.21-0.61)/10%, P = 0.0002] adjustment; the association was again explained by poorer post-ART CD4/ viral load in those with lower pre-ART %IC.
Conclusions: Higher levels of engagement in-care are associated with reduced mortality at all stages of infection, including in those who initiate ART.