Emergency Department Visits for Cardiovascular and Cerebrovascular Events Related to California Wildfires in 2015
•Air pollutants exacerbate asthma and reactive airway disease; however, less evidence for cardiovascular and cerebrovascular disease outcomes, despite biological plausibility.
•Fine particulate matter (PM2.5) can increase systemic inflammation and coagulation, elevating the risk of cardiovascular events such as ischemic heart disease, and stroke
Time series of ED visits in 9 /15 Air Basins from 5/1/2015 - 9/30/2015. Tested the association between PM2.5 exposure and health outcomes.
•Healthcare utilization data: California Office of Statewide Health Planning and Development (OSHPD) Emergency Department Dataset (EDD) and Patient Discharge Dataset (PDD)
•Air quality data: Satellite data from National Oceanic and Atmospheric Administration (NOAA) Hazard Mapping System (HMS) to estimate the density of PM2.5 with three categories of exposure:
Light (5 µg/m3), Medium (16 µg/m3), Dense (27 µg/m3)
Statistical Modeling and Analysis
•Population-based epidemiological analysis to examine zip code-level associations between daily wildfire smoke PM2.5 and health outcomes.
•PM2.5 exposures were lagged up to 7 days.
•A Poisson regression model stratified by age and sex; terms for seasonality, day of week, temperature and relative humidity.
•Cardiovascular – Strong associations with ischemic heart disease, myocardial infarction, dysrhythmia, heart failure, and pulmonary embolism, primarily among adults 65 years and older.
•Cerebrovascular/Stroke – Association with all strokes, ischemic strokes, and TIA, primarily among adults 65 years and older.
•Respiratory – Smoke exposure associated with asthma, COPD, and pneumonia ED visits, as reported elsewhere.
•Controls – No association with acute appendicitis; long-bone fractures were associated with smoke exposure among older adults and women – potentially due to evacuation-related trauma or cardiac-related falls.
•Strengthens the evidence of association between wildfire smoke exposure and cardiovascular disease and stroke
•Implications for frontline providers and public health officials for identifying susceptible populations, mitigating risk for individual patients, and planning for hospital surges during wildfire events in stroke centers and hospitals with cardiac catheterization facilities