Predictors of unsuccessful interim treatment outcomes of multidrug resistant tuberculosis patients

Interim treatment outcomes at 6-months for multidrug-resistant tuberculosis (MDR-TB) treatment are among the most basic performance monitoring and key evaluation indicators in the Stop and End TB strategy of the World Health Organization (WHO). Therefore, this study was conducted to evaluate the interim treatment outcomes of MDR-TB patients in Pakistan.

This study was conducted at the Programmatic Management Unit for Drug-resistance TB (PMDT) site of the National Tuberculosis Program (NTP), Pakistan. It is located in the Chest Disease Unit (CDU) of the Bahawal Victoria Hospital (BVH), Bahawalpur, Punjab, Pakistan. Data was collected between April 1, 2014 and December 31, 2015. The medical records, Electronic Nominal Recording Reporting System (ENRS) data and MRD-TB notification forms of the MDR-TB patients registered at the PMDT site were reviewed to obtain data. For reporting and calculation of interim treatment outcomes, standardized WHO methodology was adopted. Simple logistic regression analysis was used to examine the possible association between the dependent variable (i.e. unsuccessful interim treatment outcome) and selected socio-demographic and clinical variables.

A total of 100 drug-resistant TB (DR-TB) patients (all types) were registered during the study period. Out of these, 80 were MDR-TB patients for whom interim results were available. Out of the 80 MDR-TB cases, 48 (60%) were classified under the successful interim treatment outcome category. The remaining 40% had unsuccessful 6-month treatment outcomes and 12 (15%) patients died, while nine (11.3%) were lost to follow-up by six months. The final predictors of unsuccessful interim treatment outcomes were; being resistant to ofloxacin (AOR 3.23, 95% CI 0.96–10.89; p-value = 0.04), having above normal baseline serum creatinine levels (AOR 6.49, 95% CI 1.39–30.27; p-value = 0.02), and being culture positive at the second month of treatment (AOR 6.94, 95% CI 2–24.12; p-value = 0.01).

Despite free treatment and programmatic efforts to ensure patient adherence, the high rate of unsuccessful interim treatment outcomes is concerning. The identified risk factors for unsuccessful interim treatment outcomes in the current study provides clinicians an opportunity to identify high-risk patients and ensure enhanced clinical management and greater treatment success rates.