Adherence to Tuberculosis Infection Treatment and its Impact on Prevention of Tuberculosis Reactivation: A Retrospective Cohort Study from Taiwan

Treatment for tuberculosis infection (TBI) is often discontinued owing to adverse drug effects. The impact of treatment completion on TB reactivation remains poorly understood. We conducted a retrospective analysis of 1432 patients at one medical centre in Taiwan from 2016 to 2021. Patients with TBI were divided into three groups: non-initiation (N), incomplete treatment (IC), and complete treatment (C). Those exposure to TB but without TBI formed a control group. TB reactivation was analysed using multivariable Cox regression models, with follow-up for up to three years. The overall TB reactivation rate was 2.3 % (34/1432), ranging from 6.1 % in the TBI (N) group (n = 378), 2.1 % in the TBI (IC) group (n = 330), 0.5 % in the TBI (C) group (n = 430), and 0.7 % in the control group (n = 294). TBI treatment was independently associated with a reduced risk of TB reactivation. The adjusted hazard ratio (aHR) for TBI (IC) versus TBI (N) was 0.32 (95 % CI 0.12-0.85, p = 0.022), and for TBI (C) versus TBI (N), the aHR was 0.05 (95 % CI 0.01-0.29, p < 0.001). Each 10 % increase in treatment adherence rate resulted in a 23 % reduction in the risk of TB reactivation (aHR 0.77, 95 % CI 0.67-0.88, p < 0.001). TBI treatment, prescribed to 67 % and completed by 38 % of patients, significantly reduces TB reactivation risk, especially with high adherence. Enhancing adherence, particularly among elderly patients and those with comorbidities, is crucial for improving the effectiveness of TBI treatment.