Risk of mortality and clinical outcomes associated with healthcare delay among patients with tuberculosis.

BACKGROUND

To eliminate tuberculosis (TB), World Health Organization (WHO) initiated "The End TB Strategy" with the goal of a 95% reduction in deaths. While many resources are contributed to eradicating TB, a substantial number of TB patients are still unlikely to receive timely treatment. Thus, we aimed to measure healthcare delay and its association with clinical outcomes from 2013 to 2018.

METHODS

We conducted a retrospective cohort study using linked data of the National Tuberculosis Surveillance Registry and the health insurance claims data of South Korea. We included incident TB patients, and healthcare delay was defined as the period between the first medical visit with TB-related symptoms and the initiation of an anti-TB regimen. We described the distribution of healthcare delay, and the study population was classified into two groups with mean as a cutoff. The association between healthcare delay and clinical outcomes (all-cause mortality, pneumonia, progression to multi/extensively drug-resistant, intensive care unit admission, and mechanical ventilation use) was evaluated using the Cox proportional hazard model. Several stratified and sensitivity analyses were also conducted.

RESULTS

Among 39,747 patients with pulmonary TB, mean healthcare delay was 42.3 days and delayed and non-delayed groups, classified by mean (or average), were 10,680 (26.9%) and 29,067 (73.1%), respectively. Healthcare delay was associated with an increased risk of all-cause mortality (HR 1.10, 95% CI 1.03-1.17), pneumonia (HR 1.13, 95% CI 1.09-1.18), and mechanical ventilation use (HR 1.15, 95% CI 1.01-1.32). We also observed the duration-response of healthcare delay. Stratified analyses showed patients with respiratory diseases were at higher risk, and consistent results were observed in sensitivity analyses.

CONCLUSIONS

We observed a substantial number of patients experiencing healthcare delays, and it was associated with the deterioration of clinical outcomes. Our findings suggest that attention from authorities and healthcare professionals is needed to attenuate the preventable burden caused by TB through timely treatment.