Study of tuberculosis and AIDS stigma as barriers to tuberculosis treatment adherence using validated stigma scales.

BACKGROUND: Adherence to tuberculosis (TB) treatment is important for TB control. The effect of stigma on adherence has not been well quantified. OBJECTIVE: To identify the effects of TB and acquired immune-deficiency syndrome (AIDS) stigma on missed doses during TB treatment. DESIGN: Validated TB and AIDS stigma scales assessing perceived and experienced/felt stigma were administered in a prospective cohort of 459 TB patients at TB treatment initiation and after 2 months. Repeated measures and multivariable models estimated the effects of stigma on the rate of missed doses. RESULTS: Fifty-six per cent of patients missed no doses, and associations between stigma and missed doses were minimal. Heterogeneity of effects was observed, how- ever, with higher experienced and felt TB stigma increasing missed doses among women (adjusted RR 1.22, 95%CI 1.10-1.34) and human immunodeficiency virus (HIV) co-infected patients (aRR 1.39, 95%CI 1.13-1.72). Experienced and felt AIDS stigma also increased missed doses among HIV co-infected patients (aRR 1.43, 95%CI 1.31-1.56). CONCLUSION: Stigma has a minimal effect in this population with good adherence. Among women and HIV co-infected patients, however, experienced and felt stigma, and not perceived stigma, increased the rate of missed doses. Further research is needed to determine if stigma or coping interventions among these subgroups would improve adherence.