Prevalence and predictors of default with tuberculosis treatment in Sri Lanka

The objectives of this study were to determine the default rate and predictors for default in patients undergoing antituberculosis treatment. All consenting patients with a confirmed diagnosis of tuberculosis admitted to a unit of the Chest Hospital, Welisara, Sri Lanka from April 2001 to April 2002 were recruited into the study. Personal and follow-up data were recorded on a pre-tested questionnaire and data sheet, respectively. A defaulter was defined as a patient who interrupted treatment for more than two consecutive months before the end of the course of treatment. Of the 892 patients recruited, 770 were new cases and 122 were relapses. The default rates were 10.3% (95% CI: 8.3-12.6) and 30.3% (95% CI: 22.7-38.1) among new cases and retreatment cases, respectively, during the intensive phase of treatment and 10.9% (95% CI:8.7-13.3) and 16.5% (95% CI:9.7-25.5), respectively, during the continuation phase. Ninety percent of new cases and 94% of retreatment cases were sputum positive for acid-fast bacilli at diagnosis. Two hundred five patients (22.9%) defaulted on treatment (95% CI: 20.3-25.8). Using logistic regression analysis, regular smokers (OR = 1.9), smear positive patients who were previous defaulters (OR = 2.4) and patients having involvement of less than 3 zones of the lung on chest x-ray (OR = 0.5) were more likely to default compared to patients who did not smoke regularly, smear positive patients who had relapsed after taking the full course of treatment and patients with less lung involvement. Skilled and unskilled laborers were the most likely occupation to default (OR = 2.03) followed by sales personnel (OR = 2.00), compared to the unemployed or home-bound. A high default rate of 23% was observed among the study participants. Smoking status, occupation, history of treatment compliance of the patient, and extent of lung involvement were predictors for defaulting.