Adherence to tuberculosis infection treatment and its impact on prevention of tuberculosis reactivation: A retrospective cohort study from Taiwan.

BACKGROUND: Treatment for tuberculosis infection (TBI) is often discontinued owing to adverse drug effects. The impact of treatment completion on TB reactivation remains poorly understood.

METHODS: 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.

RESULTS: The overall TB reactivation rate was 2.3&#x202f;% (34/1432), ranging from 6.1&#x202f;% in the TBI (N) group (n&#x202f;=&#x202f;378), 2.1&#x202f;% in the TBI (IC) group (n&#x202f;=&#x202f;330), 0.5&#x202f;% in the TBI (C) group (n&#x202f;=&#x202f;430), and 0.7&#x202f;% in the control group (n&#x202f;=&#x202f;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&#x202f;% CI 0.12-0.85, p&#x202f;=&#x202f;0.022), and for TBI (C) versus TBI (N), the aHR was 0.05 (95&#x202f;% CI 0.01-0.29, p&#x202f;<&#x202f;0.001). Each 10&#x202f;% increase in treatment adherence rate resulted in a 23&#x202f;% reduction in the risk of TB reactivation (aHR 0.77, 95&#x202f;% CI 0.67-0.88, p&#x202f;<&#x202f;0.001).

CONCLUSIONS: TBI treatment, prescribed to 67&#x202f;% and completed by 38&#x202f;% 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.