Determinants of change in CD4 count and relationship with survival among children with HIV in Ethiopia.

We identify the determinants of the change in CD4 cell count and survival time of children living with HIV taking antiretroviral therapy. In a retrospective study, a cohort of 201 children living with HIV/AIDS aged less than 15 years were followed from October 2013 to March 2017. Separate linear effect models were done for the longitudinal outcome of CD4 cell count. The Cox PH model was conducted for the time-to-event outcome. Joint modeling was performed both for the longitudinal and survival outcomes, results were compared with the separate analysis. However, with the specific interest in identifying the determinants and characterizing the relationship between longitudinal CD4 cell count and time-to-event outcomes, the study focused on joint modeling. The finding from the joint model indicated that the estimated association parameter was -0.10, this shows lower values of CD4 cells associated with higher death. Seemingly; observation time, age, WHO clinical stages, history of Tuberculosis (assuming that Tuberculosis is active), and functional status were determinants for the mean change in the square root of CD4 cell count. Furthermore, WHO clinical stages, functional status, history of TB, and Body Mass Index have a significant negative impact on the survival probabilities of children living with HIV.