Factors associated with low tuberculosis preventive therapy prescription rates among health care workers in rural South Africa

BACKGROUND: Despite extensive rollout of tuberculosis preventive therapy (TPT) in South Africa to reduce the incidence of tuberculosis among people living with HIV (PWH), rates of initiation and completion have remained suboptimal. OBJECTIVE: This study aimed to identify factors associated with low TPT prescription rates among health care workers (HCWs) in rural South Africa. METHODS: A cross-sectional study was conducted using an anonymous 39-item questionnaire guided by the Consolidated Framework for Implementation Research (CFIR). HCWs from a government district hospital and 14 primary healthcare clinics (PHCs) in the rural Msinga sub-district of KwaZulu-Natal were surveyed from November 2019 to January 2020. Self-reported data on prescription rates as well as knowledge, attitudes, beliefs, and practices regarding isoniazid preventative therapy, the current TPT regimen, were obtained. Factor analysis and logistic regression were used to determine associations with low prescription rates (< 50% of PWH) for TPT prescribers, and results were placed within CFIR-driven context. RESULTS: Among 160 HCWs, the median (IQR) age was 39 (33–46) years, 76% were women, 78% worked at a PHC, and 44% had experience prescribing TPT. On multivariable analysis, prescribers (n = 71) who believed their patients would not disclose TPT use to others were significantly less likely to prescribe TPT (aOR 4.19 95% CI 1.35–13.00; p = 0.01). Inadequate isoniazid supplies trended towards significance (aOR 10.10 95% CI 0.95–106.92; p = 0.06) in association with low prescription rates. CONCLUSIONS: Strengthening HCW training to emphasize TPT prescription to all eligible PWH regardless of beliefs about patient disclosure and ensuring a consistent isoniazid supply at the health systems-level are both critical steps to enhancing TPT implementation in rural South Africa.