Application of joint modeling on the determinants of TB Status and CD4 cell count among antiretroviral therapy attendants in Gondar teaching referral hospital, Gonder, Ethiopia

East African regions were highly affected by tuberculosis and the human immunodeficiency virus. The main objective was to identifying the associated factors with tuberculosis and CD4 cell count of patients in Gonder teaching referral hospital, Gonder, Ethiopia. A retrospective cohort study was conducted on AIDS patients from 1 January 2018 - to 30 January 2020. This study used joint mixed model, and individual profile plot to identify factors and the changeability inside and between patients respectively. The mean with a standard deviation of weight and a serum hemoglobin concentration of patients were 55.48 (10.21) kilograms and 18.25 (33.028) grams per decilitre respectively.This study shows an opportunistic infection, weight, and serum hemoglobin concentration were significantly associated with the log CD4 cell count and tuberculosis status of patients. The patient who has other diseases is 5.04 more likely to be co-infected with HIV and TB diseases. And also, the estimated odds of being co-infected in both diseases were increased by 1.14 and 1.05 times when a unit change in weight and hemoglobin respectively. Moreover, the estimated odd of patients who have no other related disease were 51.13% less likely to be co-infected with both diseases.