Determinants of HIV interruption in treatment in Murang'a County, Kenya: a sequential explanatory mixed-methods study.

Globally, approximately one-in-four people living with HIV (PLHIV) experiences interruption in treatment (IIT), risking viral rebound, transmission, morbidity, and mortality. Murang'a County reported 82% viral suppression coverage, below Kenya's 94%. This study assessed IIT magnitude and determinants using sequential-explanatory mixed methods across nine high-volume facilities (Jan 2023-Jun 2024). PLHIV missing clinical appointments by >30 days were compared with those retained using descriptive statistics, chi-square, and logistic regression. Among 11,472 PLHIV, 6.5% (742) experienced IIT; 50.8% (377) did not return to care. IIT was associated with age 20-24 (aRR =2.02), 25-49 years (aRR = 2.27), male (aRR = 1.42), viral non-suppression (aRR = 6.35), invalid viral load (aRR = 9.59), ART duration 6-12 months (aRR = 4.96), and WHO stages 3&4 (aRR = 2.08) (All p < 0.001). Focus group discussions revealed HIV undetectable VL equals untransmittable knowledge gaps, negative service experiences, transport costs, long waits, frequent clinic visits, pill burden, stigma, and prayers replacing ART barriers. PLHIV with IIT experienced prolonged care disengagement, with higher rates among younger PLHIV, men, those with unsuppressed and older VL, early ART, and advanced HIV disease, influenced by individual, healthcare systems, treatment-related, and sociocultural barriers. Strengthening early tracing, differentiated service delivery, longer-acting ART, VL monitoring adherence, HIV literacy, and stigma reduction is critical to improving retention.