Background: The burden of HIV remains heaviest in resource-limited settings, where problems of losses to care, silent transfers, gaps in care, and incomplete mortality ascertainment have been recognized.

Methods: Patients in care at Academic Model Providing Access to Healthcare (AMPATH) clinics from 2001-2011 were included in this retrospective observational study. Patients missing an appointment were traced by trained staff; those found alive were counseled to return to care (RTC). Relative hazards of RTC were estimated among those having a true gap: missing a clinic appointment and confirmed as neither dead nor receiving care elsewhere. Sample-based multiple imputation accounted for missing vital status.

Results: Among 34,522 patients lost to clinic, 15,331 (44.4%) had a true gap per outreach, 2754 (8.0%) were deceased, and 837 (2.4%) had documented transfers. Of 15,600 (45.2%) remaining without active ascertainment, 8762 (56.2%) with later RTC were assumed to have a true gap. Adjusted cause-specific hazard ratios (aHRs) showed early outreach (a ≤8-day window, defined by grid-search approach) had twice the hazard for RTC vs. those without (aHR = 2.06; P < 0.001). HRs for RTC were lower the later the outreach effort after disengagement (aHR = 0.86 per unit increase in time; P < 0.001). Older age, female sex (vs. male), antiretroviral therapy use (vs. none), and HIV status disclosure (vs. none) were also associated with greater likelihood of RTC, and higher enrollment CD4 count with lower likelihood of RTC.

Conclusion: Patient outreach efforts have a positive impact on patient RTC, regardless of when undertaken, but particularly soon after the patient misses an appointment.