Predictors of CD4 cell count progression over time among adolescents and young adults transitioning to adult-oriented HIV care in Southern Ethiopia from 2017 to 2021: a retrospective cohort study

Abstract Background Human immunodeficiency virus (HIV), a viral infection impacting CD4 cells, requires an understanding of factors influencing CD4 cell counts to reduce acquired immunodeficiency syndrome(AIDS)-related morbidity and mortality. Despite its importance, no studies have examined predictors of CD4 cell count progression post-transition to adult-oriented HIV care in Ethiopia. This study aimed to identify predictors affecting CD4 cell count trends among adolescents and young adults transitioning to adult-oriented HIV care. Therefore, this study aimed to identify the predictors that affect the trends of CD4 cell count over time among adolescents and young adults who transitioned to adult-oriented HIV care. Methods A retrospective cohort study was conducted among 206 adolescents and young adults who transitioned to adult-oriented HIV care and had at least two CD4 cell counts in eight selected health facilities in Southern Ethiopia. These facilities were chosen due to their high volume of people living with HIV. A multivariable linear mixed effect model was fitted to identify the predictors of CD4 cell count progression through time. Multi-collinearity between variables was checked using the variance inflation factor. Model comparisons were done using Akaike and Bayesian information criteria. Regression coefficients with 95% confidence intervals (CI) and P-value ≤ 0.05 were used to measure the strength of association and significance level. Results The average CD4 cell count was raised by 6.7 cells/mm3 every six months among the study participants. Transitioning at the age of 18 or older (β = 204.71; 95% CI = 81.86347, 327.5574; P