Impact of Coronavirus Disease 2019 Emergency Declarations on Surgeries for Deep Neck Infection Incidence in Japan.

Introduction: Deep neck infections are lethal diseases; however, factors related to their prevention remain unclear. The national emergency declaration in April 2020, in response to COVID-19, spurred widespread adoption of nonpharmaceutical interventions (NPIs) such as hand washing, mask wearing, and social distancing.

Methods: This retrospective cohort study examines the impact of these interventions on the incidence of deep neck infections in Japan through interrupted time series analysis using National Database of Health Insurance Claims and Specific Health Checkups of Japan Open Data. Aggregated yearly and monthly data from fiscal year 2014 to 2021 were analyzed. This study aimed to examine the time series changes in Japan, including the impact of COVID-19, by focusing on retropharyngeal, peritonsillar, and deep neck abscess surgeries.

Results: A significant seasonal variation was observed in peritonsillar abscesses, with a peak in July. We assessed changes in surgery for deep neck infections before and after the emergency declaration. Interrupted time series analysis revealed changes in surgery for retropharyngeal abscess (level change, 0.59; 95% confidence interval [CI], 0.40-0.86; slope change, 0.98; 95% CI, 0.94-1.02), peritonsillar abscess (level change, 0.84; 95% CI, 0.75-0.94; slope change, 1.00; 95% CI, 0.99-1.01), and deep neck abscess (level change, 0.91; 95% CI, 0.77-1.08; slope change, 0.99; 95% CI, 0.97-1.01).

Conclusions: These findings suggest that the NPIs implemented due to the emergency declaration are effective in reducing the need for surgical intervention in retropharyngeal and peritonsillar abscess cases, highlighting the potential for these measures to prevent serious infections.