Patterns of Patient Engagement in Antiretroviral Therapy Care: a retrospective cohort study in Malawi.

BackgroundConsistent engagement in antiretroviral therapy (ART) care is crucial for health outcomes and HIV transmission reduction. This study examined the first two years of ART engagement patterns in two public ART clinics in Lilongwe, Malawi. Routine retention support is provided using ART "Buddies" or a two-way texting (2wT) system for those with phones and interest. MethodsART engagement patterns were analysed across six-month intervals (>0-6, >6-12, >12-18, >18-24). Patients retained on ART were categorised as continuously engaged (attended all appointments within 13 days), cyclical engagement (returned late (14-59 days) at least once), and re-engaged (missed an appointment by [≥]60 days but returned to care). Clients who disengaged (lost to follow-up (LTFU), transferred out, stopped, or died) at any interval were assigned that outcome. Engagement patterns were visualised using a Sankey chart. ResultsAmong 6,303 clients, 1,030 (16%) were in the Buddy support group with phone access, 4,850 (77%) without phone, and 423 (7%) in the 2wT support group. 5,300 (84%) clients were grouped into 33 common engagement patterns over 24 months; 1,003 (16%) of clients illustrated fewer common patterns. By 24 months, 3,368 (53%) were retained on ART: 296 (70%) of 2wT; 2,793 (58%) of Buddy with phone access; and 3,367 (27%) of Buddy without phone access. Among the 3,368 clients retained on ART at 24 months, 1,836 (55%) were continuously engaged, 1,031 (30%) had cyclical engagement, and 500 (15%) re-engaged after LTFU. Overall, 1836 (29% of the total cohort of 6,303) continuously engaged in care over 24 months. In the six-month interval analysis, clients aged 50+ had the highest proportion (n=184, 70%) of continuous engagement overall, compared to individuals aged 35-49 years (n=832, 58%) and 18-34 years (n=820, 49%). 2wT clients showed the highest continuously engagement up to 18 months (70% at 0-6 months, 72% at >6-12 months, and 81% at >12- 18 months), compared to Buddy groups (with phone access:57%, 58%, 76%; without phone access: 30%, 33%, 62%). ConclusionA small proportion of clients were continuously on ART over the first 24 months of ART. Older clients and 2wT participants had more favourable ART engagement patterns; those without phone access faired worst. While most ART clients followed similar ART engagement patterns, a few showed varying trajectories. Tailored retention support based on engagement patterns could improve long-term retention in ART care.