ABSTRACT Background The long‐term impact of COVID‐19 on tuberculosis (TB) is concerning. This study assessed whether COVID‐19 was associated with an increased risk of active TB treatment risk in Japan using a nationwide propensity score–matched cohort design. Methods A retrospective cohort study used Japan's National Insurance Database from January 2020 to December 2022. COVID‐19 patients were matched 1:1 with controls using propensity scores based on age, sex, immunosuppressants use, Charlson comorbidity index, related medical conditions, healthcare utilization and prior TB history. The primary outcome was initiation of isoniazid‐based therapy plus rifampin with a TB‐related ICD‐10 diagnosis code. Cox proportional hazards models estimated hazard ratios (HRs) for COVID‐19's effect on TB treatment initiation. Results After matching, 3,097,422 individuals were included per group. During 8‐month median follow‐up, 886 participants initiated TB treatment. The HR among COVID‐19 infected individuals was 4.14 (95% CI: 3.51–4.89) versus matched controls. Subgroup analyses showed interaction between prior TB history and COVID‐19, with HR of 14.7 (5.35–40.2) in those with prior TB history, versus those without (HR 3.84, 95% CI 3.24–4.54). Risk remained elevated in participants without hospitalization (HR 3.96, 95% CI 3.35–4.68). Conclusions This study provides robust population‐based evidence demonstrating a moderate association between prior COVID‐19 and subsequent initiation of active tuberculosis treatment, particularly in those with prior TB history.
Miyamori et al. (Tue,) studied this question.