Risk factors associated with default from multidrug-resistant tuberculosis treatment, South Africa, 1999-2001

Multidrug-resistant tuberculosis (MDR-TB) treatment centers in five provinces, South Africa.

To estimate the mortality and evaluate risk factors associated with default from MDR-TB treatment.

Using registries and a standardized questionnaire, we conducted a case-control study among patients diagnosed and treated for MDR-TB. Cases were defined as patients who began MDR-TB treatment between 1 October 1999 and 30 September 2001 and defaulted from treatment for more than 2 months; controls were defined as patients who began MDR-TB treatment during the same time and were cured, completed or failed.

After initial identification and reclassification, 269 cases and 401 controls were confirmed eligible for interview. Further investigation revealed that 74 (27%) cases and 44 (10%) controls had died. Among 96 cases located who consented and were interviewed, 70% had defaulted after receiving at least 6 months of treatment. In a multivariate model, the strongest individual risk factors for default included reporting smoking marijuana or mandrax during treatment, and having an unsatisfactory opinion about the attitude of health care workers.

Mortality among MDR-TB defaulters was high. Interventions to reduce default from MDR-TB treatment should center on substance abuse treatment, patient education and support and improving provider-patient relationships.