(1201) A longitudinal analysis of acute and chronic sinusitis hospitalization trends in California, 2015-2024

Introduction: While most episodes of acute and chronic sinusitis are managed in outpatient settings, severe cases may require hospitalization. This study assessed 10-year trends in inpatient admissions for sinusitis in California to characterize evolving healthcare utilization patterns

Methods: This longitudinal study analyzed hospitalization trends (2015–2024) using the California Health and Human Services Open Data Portal. Subjects were identified via ICD-9-CM codes (prior to October 2015) and ICD-10-CM codes thereafter. The primary outcome was the annual admission rate per 100,000 total inpatient admissions. Linear trends were evaluated using the Cochran-Armitage test. A sensitivity analysis excluding 2020–2021 data controlled for the confounding influence of the COVID-19 pandemic.

Results: Among 163,097 sinusitis-related admissions, a significant linear decline occurred over the 10-year period (P < 0.0001). The acute sinusitis admission rate decreased 24.5% (116 to 88 per 100,000), and the chronic sinusitis rate declined 32.6% (463 to 312 per 100,000). Sensitivity analysis confirmed that the downward trend remained statistically significant independent of pandemic-era fluctuations (P < 0.001).

Conclusions: Inpatient admissions for acute and chronic sinusitis in California decreased significantly from 2015 to 2024. This persistent decline suggests the trend is driven by fundamental shifts in clinical practice—such as optimized outpatient management and "watchful waiting"—rather than temporary external disruptions.