Bayesian Survival Analysis of Adult Tuberculosis Patients: the Case of Lemlem Karl Hospital, Maichew, Southern Tigray.

Abstract

Tuberculosis is an airborne disease caused by the bacterium Mycobacterium tuberculosis, primarily affects the lungs. Transmission occurs through the air when individuals with pulmonary TB are not undergoing proper treatment. This study aimed to identify factors affecting the survival time of adult TB patients in LKH, Maichew, and Southern Tigray. To address the objective of this study, 242 adult TB patients were included in the study based on data taken from the medical records of patients enrolled from July; 2020 to January; 2024. Almost half, 50.4%, of the adult TB patients were female. Kaplan Meier plots were used for comparison of survival function; Bayesian survival models were used to identify factors affecting the survival time of adult TB patients. Of the total patients in the study 178 (73.6%) were censored. The estimated median survival time of patients was 26 months. Bayesian log-normal accelerated failure time model using MCMC and INLA method fit adult TB data better than other Bayesian accelerated failure time models used in this study. The Bayesian log-normal accelerated failure time model using the INLA method was preferable to the MCMC method due to smaller standard error and narrow credible interval. The results of this model show that the survival time of adult TB patients is significantly affected by age, residence, body weight, HIV status, BMI, dose level and cigarette smoking of adult TB patients(pvalue<0.05). Bayesian log-normal accelerated failure time model using the INLA method describes the adult TB dataset well. From the Bayesian result, the risk factors for the survival time of adult TB patients were age group (31 to 45, 𝛾 = 0.8607),(46 to 60, 𝛾 = 0.7189)and( >60, 𝛾 = 0.6637);residence(rural,𝛾 =0.7408); HIV (Positives, 𝛾 = 0.68386); Dose (III, 𝛾 = 0.6570) ,IV 𝛾 = 0.9512),BMI(Overweight, 𝛾 = 0.8607) and (Obese 𝛾 = 0.0779); base line weight(> 50kg, 𝛾 = 0.8693) and (smokers, 𝛾 = 0.8607) at 95% credible interval and those factors were prolonged the timing death of adult TB patients. Therefore, health professionals should focus on the identified factors to improve the survival time of TB patients.