Abstract
<title>Abstract</title> <p>Background Intensive Adherence Counselling (IAC) is the recommended intervention for people living with HIV who experience virological non-suppression. However, evidence on retention across the IAC cascade and factors influencing sustained engagement among adolescents and young people living with HIV (AYPLHIV) remains limited. We assessed retention in IAC, its associated factors, and its relationship with viral load suppression among virally non-suppressed AYPLHIV in east-central Uganda. Methods We conducted a sequential explanatory mixed-methods study across 32 public health facilities. Quantitative data were retrospectively extracted for 580 virally non-suppressed AYPLHIV aged 10–24 years enrolled in IAC between 2019 and 2024. Retention was defined as completion of all recommended IAC sessions. Modified Poisson regression with robust standard errors identified factors associated with retention. Twelve purposively selected participants, including AYPLHIV, caregivers, and healthcare providers, participated in in-depth interviews. Qualitative data were analysed using a deductive thematic approach guided by the Capability, Opportunity, Motivation-Behaviour framework. Results Participants were predominantly female (62.8%) with a median age of 16.4 years (IQR: 12.9–21.2). Retention declined progressively across the IAC cascade from 100% at initiation to 86.7% at IAC-1, 71.2% at IAC-2, and 64.8% at IAC-3. Participants who completed all IAC sessions achieved significantly higher viral suppression than those who did not complete the cascade (p < 0.001). Retention was higher among participants receiving peer support (aPR = 1.35, 95% CI: 1.17–1.55), counsellor-led IAC (aPR = 2.80, 95% CI: 1.53–5.13), and those living within 5 km of a facility (aPR = 1.22, 95% CI: 1.01–1.49). Lower retention was associated with difficulty coping with HIV status, disruption of differentiated service delivery pathways, treatment supporter involvement and VHT support. Qualitative findings attributed disengagement to emotional distress, transport barriers, and substitution of formal counselling by family and community support systems. Conclusions Retention in IAC among virally non-suppressed AYPLHIV was suboptimal and strongly associated with viral load suppression. Strengthening peer support, psychosocial care, counsellor-led services, and integration of IAC within differentiated HIV service delivery models may improve retention and treatment outcomes among AYPLHIV.</p>