Evaluation of Time to Sputum Smear Conversion and its association with Treatment Outcomes among Drug Resistant Tuberculosis Patients; A retrospective Record Viewing Study

Background: This study examined the time to sputum smear and culture
conversion and determinants of conversion, as well as variables associated with
treatment outcomes among drug-resistant pulmonary tuberculosis (DR-PTB) cases.
Methods: The electronic database and written medical records of patients were
utilized to assess the sociodemographic, clinical, microbiological, and treatment
characteristics and outcomes of study participants.
Results: Among 736 patients with pulmonary tuberculosis (PTB), the mean age
was 36.5 ± 16.5 years, with males comprising 53.4% and a mean weight of 47.76 ±
11.97 kg. The median time period for sputum smear conversion and sputum
culture conversion was a month. The first-month culture conversion (p < 0.001,
aOR = 5.817, and 95% CI = 3.703–9.138) was the determinant of sputum smear
conversion and receiver operating curve analysis with AUC = 0.881, 95% CI =
0.855–0.907, and p < 0.001, which showed a high level of predictive ability for the
regression model for the initial sputum smear conversion. However, the firstmonth
sputum conversion (p < 0.001, aOR = 7.446, and 95% CI = 4.869–11.388)
was attributed to sputum culture conversion, and the model has shown excellent
predictive ability for regression with ROC curve analysis demonstrating AUC =
0.862, 95% CI = 0.835–0.889, and p < 0.001. A total of 63.2% of patients showed
favorable treatment outcomes, with 63.1% of cases achieving treatment-cured
status. The previous use of SLD, history of smoking, duration of illness ≤ 1 year,
extensively drug-resistant tuberculosis, and first-month sputum conversion were
the variables attributed to favorable treatment outcomes observed in drugresistant
pulmonary tuberculosis cases. ROC curve analysis with AUC = 0.902,
95% CI = 0.877–0.927, and p < 0.001) has shown outstanding ability for
regression model prediction for the variables influencing treatment outcomes.
Conclusions: Within 2months of treatment, most patients had converted their
sputum cultures and sputum smears. The determinants of early sputum smear
and sputum culture conversion, as well as favorable treatment outcomes, were
identified. These factors should be considered during the design and implementation
of effective strategies for drug-resistant tuberculosis control programs.