Prevalence of psychological distress and associated factors in tuberculosis patients in public primary care clinics in South Africa

Background: Psychological distress has been rarely investigated among tuberculosis patients in low-resource settings despite the fact that mental ill health has far-reaching consequences for the health outcome of tuberculosis (TB) patients. In this study, we assessed the prevalence and predictors of psychological distress as a proxy for common mental disorders among tuberculosis (TB) patients in South Africa, where over 60 % of the TB patients are co-infected with HIV. Methods: We interviewed 4900 tuberculosis public primary care patients within one month of initiation of anti-tuberculosis treatment for the presence of psychological distress using the Kessler-10 item scale (K-10), and identified predictors of distress using multiple logistic regressions. The Kessler scale contains items associated with anxiety and depression. Data on socio-demographic variables, health status, alcohol and tobacco use and adherence to anti-TB drugs and anti-retroviral therapy (ART) were collected using a structured questionnaire. Results: Using a cut off score of >= 28 and >= 16 on the K-10, 32.9 % and 81 % of tuberculosis patients had symptoms of distress, respectively. In multivariable analysis older age (OR = 1.52; 95 % CI = 1.24-1.85), lower formal education (OR = 0.77; 95 % CI = 0.65-0.91), poverty (OR = 1.90; 95 % CI = 1.57-2.31) and not married, separated, divorced or widowed (OR = 0.74; 95 % CI = 0.62-0.87) were associated with psychological distress (K-10 >= 28), and older age (OR = 1.30; 95 % CI = 1.00-1.69), lower formal education (OR = 0.55; 95 % CI = 0.42-0.71), poverty (OR = 2.02; 95 % CI = 1.50-2.70) and being HIV positive (OR = 1.44; 95 % CI = 1.19-1.74) were associated with psychological distress (K-10 >= 16). In the final model mental illness co-morbidity (hazardous or harmful alcohol use) and non-adherence to anti-TB medication and/ or antiretroviral therapy were not associated with psychological distress. Conclusions: The study found high rates of psychological distress among tuberculosis patients. Improved training of providers in screening for psychological distress, appropriate referral to relevant health practitioners and providing comprehensive treatment for patients with TB who are co-infected with HIV is essential to improve their health outcomes. It is also important that structural interventions are promoted in order to improve the financial status of this group of patients.