Factors affecting outcomes of individualised treatment for drug resistant tuberculosis in an endemic region.

Background: Individualised treatment regimens for drug resistant tuberculosis have improved outcomes. This retrospective observational study examined potential factors that affect individualised treatment in an endemic region, and highlighted predictors of a successful outcome.

Methods: We examined records of proven MDR, pre-XDR and XDR TB patients diagnosed and started on treatment between 2010 and 2014, and collected the following data for each patient: age, gender, comorbidities, past history of TB, diagnosis, site of disease, drug susceptibility testing (DST) results, treatment, adverse reactions to anti-tubercular drugs, treatment changes and outcomes, which were recorded as positive, negative or neutral. Tests of association were carried out between factors and outcomes, following which multiple logistic regression analysis was done to determine the predictors of a positive outcome such as patient cured after completion of treatment at 18 months or longer.

Results: Fifty-nine patients completed treatment at our centre. The median age was 26 years (range 8-65 years). There were 31 (52.5%) female patients. Forty-four (74.6%) were successfully treated over a median treatment period of 23 months (range 18-30 months). Successful outcomes were associated with age less than 45 years (P=0.01, OR=6.67, 95% CI=1.73-23.47), resistance to fewer than five drugs (P=0.001, OR=9.51, 95% CI=2.50-38.18) and susceptibility to Group 4 drugs (P=0.04, OR=4.71, 95% CI=1.03-16.83).

Conclusions: Age and drug susceptibility were important predictors of treatment outcome.