Factors associated with tuberculosis treatment default among HIV-infected tuberculosis patients in Thailand

Ensuring completion of tuberculosis (TB) treatment remains a major public health problem. In HIV-infected patients, TB is the most common severe opportunistic infection. Few studies have evaluated risk factors for TB treatment default in HIV-infected patients. We conducted a prospective, observational study of HIV-infected TB patients in Thailand. Patients underwent standardised evaluations at the beginning of TB treatment, at the end of the intensive phase and at the end of TB treatment. TB treatment outcomes were assessed according to WHO guidelines. The analysis was limited to patients who defaulted or who had treatment success. Of the 554 patients analysed, 61 (11%) defaulted. In multivariate analysis, factors associated with TB treatment default included incarceration history [adjusted odds ratio (AOR) 2.0, 95% CI 1.1-3.7), smoking (AOR 2.3, 95% CI 1.3-4.1) and having a symptom complaint score >15 (AOR 3.4, 95% CI 1.4-8.0); one marker of wealth, namely owning a refrigerator, was protective (AOR 0.4, 95% CI 0.2-0.8). Default during TB treatment was a significant problem in HIV-infected patients. Reducing default may require enhancing services for patients with a history of incarceration or smoking and designing patient-centred systems to address poverty and patient wellness.