Evaluation of Factors Related to Survival Time in HIV-Infected Persons in Mashhad, Iran, Between 1994 - 2014: A Bayesian Joint Model

Background: The prevalence of HIV is increasing in Iran, so obtaining an estimate of the survival of HIV-infected persons can be helpful to prevent and control this infection. Objectives: This research aimed to use the Bayesian joint model by which identifies factors associated with the survival and determine the relationship between the trend of CD4 + T cell counts and survival time in HIV-infected persons. Methods: In this retrospective cohort study, we collected HIV/AIDS surveillance data from Mashhad’s Counseling Center of Behavioral Diseases in the province of Khorasan Razavi, Northeast of Iran, during 1994 - 2014. Data collection included variables CD4 + T cellscount, survivaltime, andotherrelatedfactors. WeusedtheBayesianjointmodeltoestimatethesurvivaltimeandidentifythe factors associated with survival time in HIV-infected persons. Results: The study included 260 individuals, of whom 212 (81.54%) were male. The survival sub-model of the joint model identified gender (95% credible interval (CI): 0.486, 3.197) and antiretroviral treatment (95% CI: -1.935, -0.641) as the variables associated with the patients’ survival. The longitudinal sub-model, which determined the variables associated with the number of CD4 + T-cells included time (95% CI: -0.934, -0.554), age (95% CI: -0.152, -0.011), and antiretroviral treatment (95% CI: -6.193, -3.505). Conclusions: UsingCD4 + TcellsasacovariateintheBayesianjointmodel,thesurvivaltimeforHIV-infectedpersonswasestimated more precisely than separate model and it can be inferred that at the beginning of antiretroviral treatment, especially in men and controls, the CD4 + T cell counts can increase the survival time of HIV-infected persons.