Defaulter rate and predictors of defaulting of patients on anti-tuberculosis treatment

Abstract

OBJECTIVE: To determine the defaulter rate and risk factors of defaulting of patients on anti- tuberculosis treatment. METHODS: All consenting patients with a confirmed diagnosis of tuberculosis admitted to a unit at Chest Hospital, Welisara were recruited from April 2001 to April 2002 for follow up. Personal and follow up data were recorded in 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. RESULTS: Of the 892 patients recruited, 770 were new cases and 122 were relapses. Defaulter rate was 10.3%(95%CI:8.3%-12.6%) and 30.3% (95% CI:22.7%-38.1%) among new cases and re-treatment cases respectively in the intensive phase of treatment and 10.9 % (95% CI:8.7%-13.3%) and 16.5% (95% CI: 9.7- 25.5) respectively in the continuation phase. 90% of new cases and 94% of re-treatment cases were sputum positive at diagnosis. Altogether 205 (22.9%) defaulted treatment (95% CI: 20.3%-25.8%). Age, sex, occupational status, family income, regular alcohol consumption, current smoking and substance abuse were independently significantly associated (p<0.05) with defaulting. Defaulters were significantly different (p<0.05) from compliers with regard to the site of the lesion, being in new or re-treatment category (type), acid-fast bacilli in sputum and extent of lung involvement. Using logistic regression analysis, a regular smoker (OR=1.9), a smear positive defaulter (OR=2.4) and a patient having involvement of more than 3 zones of the lung on chest x-ray examination (OR=0.5) was more likely to default as compared to a patient who did not smoke regularly, a smear positive patient who had relapsed after taking the full course of treatment and a patient with less lung involvement, respectively. Of the occupational categories, skilled and unskilled labourers were most likely to default (OR=2.03) followed by sales personnel (OR=2.00) as compared to those unemployed or home-bound. Conclusions: A high defaulter rate of 23% was observed among the study participants. Smoking status, occupation, type of patient, and extent of lung involvement are predictors of defaulting.