The Indirect Impact of COVID-19 Pandemic on Mortality, Complications, and Healthcare Utilization Among Patients With Chronic Respiratory Diseases in Hong Kong: An Interrupted Time Series Analysis.

Purpose: This study aimed to investigate COVID-19's indirect influence on chronic respiratory disease (CRD) patients for two years since the COVID-19 pandemic began.

Methods: Using population-based data in Hong Kong, we included CRD patients diagnosed from January 2011 to December 2021. Interrupted Time Series Analysis were applied to assess mortality, complications, and healthcare utilization rates during the "pre-COVID-19 pandemic" (January 2012-January 2020), "initial COVID-19 pandemic" (February 2020-February 2021), and "post-initial COVID-19 pandemic" (March 2021-December 2021) periods.

Results: Among 587,049 patients with CRD, all-cause mortality had an increasing trend during the post-initial COVID-19 pandemic period (incidence rate ratio (95% CI): 1.019 (1.005, 1.034); p = 0.007), compared with pre-COVID-19 pandemic period. Nonrespiratory mortality had an increasing trend in the initial COVID-19 pandemic period (1.020 (1.006, 1.033); p = 0.004) and was higher than the pre-pandemic level in the post-initial COVID-19 pandemic. We observed abrupt declines in the incidence rates of asthma exacerbation, acute exacerbation of chronic obstructive pulmonary disease, pneumonia, and acute respiratory failure in the first month of initial COVID-19 pandemic period, remaining below pre-COVID-19 pandemic levels throughout the initial pandemic period.

Conclusion: The disruption of usual healthcare impacts mortality rates among patients with CRD without COVID-19, particularly nonrespiratory mortality. Contingency plans on continuing follow-up and monitoring of CRD patients are needed, for example, teleconsultations, shared primary care, and tele-reminders on red-flag symptoms for patients with CRD, when healthcare services may be disrupted during public health crises.