Seasonal variation in the incidence of primary intracerebral hemorrhage: a 16-year nationwide analysis

Eman Baig; Jonika Tannous; Thomas Potter; Alan Pan; Taya Prince; Gavin Britz; Farhaan S Vahidy; Abdulaziz T Bako

doi:10.3389/fneur.2023.1179317

Seasonal variation in the incidence of primary intracerebral hemorrhage: a 16-year nationwide analysis

Front Neurol. 2023 Jun 29:14:1179317. doi: 10.3389/fneur.2023.1179317. eCollection 2023.

Authors

Eman Baig¹, Jonika Tannous¹, Thomas Potter¹, Alan Pan², Taya Prince¹, Gavin Britz¹, Farhaan S Vahidy^{1

2

3}, Abdulaziz T Bako¹

Affiliations

¹ Department of Neurosurgery, Houston Methodist, Houston, TX, United States.
² Center for Health Data Science and Analytics, Houston Methodist, Houston, TX, United States.
³ Department of Population Health Sciences, Weill Cornell Medical College, New York, NY, United States.

Abstract

Introduction: Data on nationwide trends and seasonal variations in the incidence of Intracerebral Hemorrhage (ICH) in the United States (US) are lacking.

Methods: We used the Nationwide Inpatient Sample (2004-2019) and Census Bureau data to calculate the quarterly (Q1:January-March; Q2:April-June; Q3:July-September; Q4:October-December) incidence rates (IR) of adult (≥18 years) ICH hospitalizations, aggregated across Q1-Q4 and Q2-Q3. We report adjusted incidence rate ratios (aIRR) and 95% confidence intervals (CI) for differences in the quarterly incidence of ICH, as compared to acute ischemic stroke (AIS), between Q1Q4 and Q2Q3 using a multivariable Poisson regression model. We additionally performed stratified analyses across the four US regions.

Results: Among 822,143 (49.0% female) ICH and 6,266,234 (51.9% female) AIS hospitalizations, the average quarterly crude IR of ICH was consistently higher in Q1Q4 compared to Q2Q3 (5.6 vs. 5.2 per 100,000) (aIRR, CI: 1.09, 1.08-1.11)-this pattern was similar across all four US regions. However, a similar variation pattern was not observed for AIS incidence. The incidence (aIRR, CI) of both ICH (1.01, 1.00-1.02) and AIS (1.03, 1.02-1.03) is rising.

Conclusion: Unlike AIS, ICH incidence is consistently higher in colder quarters, underscoring the need for evaluation and prevention of factors driving seasonal variations in ICH incidence.

Keywords: acute ischemic stroke; incidence rate; intracerebral hemorrhage; seasonal variations; trends.