A Retrospective Comparative Study on Median Time to Sputum Culture Conversion in Multi-Drug Resistant Pulmonary Tuberculosis Patients in Pastoral and Non-Pastoral Settings in Southeast Oromia, Ethiopia

PURPOSE: Sputum culture conversion to negative is an indicator of good interim treatment outcome. Pastoralist community has lesser access to healthcare services. This study aimed to compare the time to culture conversion (TTSCC) between the pastoral and non-pastoral settings and identify its determinants among drug-resistant pulmonary TB patients. PATIENTS AND METHODS: Four hundred forty-seven drug-resistant pulmonary TB patients were included from selected hospitals of southeastern Oromia, Ethiopia. Kaplan–Meier model using the Log rank test was fit to compute and compare median TTSCC between study participants from the pastoral and non-pastoral settings. The Cox proportional hazard model was fit to identify factors associated with the TTSCC. Adjusted hazard ratio (AHR) with a 95% confidence interval (CI) was used to report the strength of association. Statistical significance was declared at p < 0.05. RESULTS: The study participants’ median age (interquartile range) was 29 (24–36) years. The overall median TTSCC among the current study participants was 67 (95% CI, 64–70) days. It was significantly different for patients from the pastoral and non-pastoral settings (p-value <0.001). The median TTSCC for patients from pastoral and non-pastoral settings was 101 (95% CI, 81–121) and 63 (95% CI, 61–64) days. To mention few determinants, patients from the pastoral setting had a 69% lower chance [HR = 0.31 (95% CI 0.24–0.41)] of shorter TTSCC than patients from the non-pastoral setting. Furthermore, patients with baseline body mass index greater than 18.5Kg/M(2) had a 35% higher chance of shorter TTSCC [HR = 1.35 (95% CI 1.07–1.71)] compared to their counterparts. CONCLUSION: The median TTSCC among the study participants from pastoral was longer than those from non-pastoral setting. The pastoral setting, under-nutrition, previous exposure to anti-TB drugs and drug regimen categories were among the notable determinants of the TTSCC among our study participants. Hence, due attention should be given to patients with these determinants during the treatment.