Catastrophic costs among tuberculosis patients in Zimbabwe: a national health facility-based survey

Abstract Background: Tuberculosis (TB) has biological and socio-economic dimensions. The socio-economic impact of TB may plunge households into financial catastrophes. The End TB strategy seeks to mitigate socio-economic factors which may act as barriers to accessing TB services. Countries have been encouraged to provide baseline estimates of catastrophic costs by 2020. We sought to determine the prevalence, risk factors and major drivers of catastrophic costs among TB patients in Zimbabwe. Methods: We conducted a nationally representative, health facility-based survey with random cluster sampling among TB patients. We enrolled patients with drug susceptible (DS-TB) and drug resistant TB (DR-TB) consecutively. We administered a standardised questionnaire to capture the costs incurred as well as lost income due to TB illness. Catastrophic costs were measured at a threshold of 20%. We did a sensitivity analysis of indirect costs using the time lost by patients in each phase of treatment. We used multivariable logistic regression to determine the risk factors for experiencing catastrophic costs. Results: A total of 841 patients were enrolled in the survey, weighted to 900 during data analysis. There were 500 (56%) males and 46 (6%) DR-TB patients. Thirty-five (72%) DR-TB patients were HIV co-infected. Overall, 80% (95% CI:77-82%) of TB patients and their households experienced catastrophic costs. The major cost drivers pre-TB diagnosis were direct medical costs. Nutritional supplements were the major cost driver post-TB diagnosis, (median cost US$360 (IQR: 240-600). Post-TB diagnosis costs were three-times higher among DR-TB [US$1,659 (653-2,787)] versus drug susceptible TB (DS-TB) affected households [US$537 (204-1,134)]. Income loss was five-times higher among DR-TB versus DS-TB patients. In multivariable analysis, household wealth was the only covariate that remained significantly associated with catastrophic costs: the poorest households had sixteen times the odds of incurring catastrophic costs compared to wealthiest households [adjusted odds ratio (aOR:15.7 95% CI:7.5-33.1)]. Conclusion: The majority of TB patients enrolled in care experienced catastrophic costs, with the highest burden on DR-TB patients. Since the major cost drivers fall outside the healthcare system, a multi-sectoral approach to TB control and linking TB patients to social protection schemes holds promise for reducing catastrophic costs in Zimbabwe.