California Wildfire Impact on Asthma and COPD Hospitalizations

Abstract

Background:

Wildfire activity in California has increased over recent years due climate change resulting in severe droughts. There are demonstrated connections between wildfire smoke exposure and respiratory health. Patients with a diagnosis of asthma and COPD have decreased lung function, higher incidence of lung infections, and increased ED visits and hospitalizations. We set out to assess the incidence of hospital admissions for asthma or COPD exacerbations during low and high wildfire season years.

Methods:

Retrospective data was analyzed from a Vizient database patients with a hospital admission for a primary diagnosis of asthma or COPD exacerbation at UC Davis Health in Sacramento California. Data was analyzed in the months of November 2018 during the infamous Camp fire that burned 153,336 acres and November 2019 when the largest fire that season, the Kincade fire, burned 77,758 acres. We then compared the admission data to Novembers 2020 and 2021 when there was a much lower fire season; 379 and 24 acres respectively. Admission rates, demographics, LOS, and SES were evaluated and compared. Descriptive statistical analysis was performed with Chi square, Student t-test, and 95% confidence intervals when appropriate.

Results:

There were 94 admissions for asthma and COPD during 2018-19 (68%) vs. 45 (32%) in 2020-21, P = .08. COPD and adult admissions during 2018-19 were 47 (65%) vs. 25 (35%) in 2020-21, P = .25. Pediatric rates of admissions during wildfires compared to low fire seasons, n = 47 (70%) vs. n = 20 (30%), P = .017. When comparing the 2018-19 admissions to the 2020-21 admissions, there were no statistically significant differences in demographics, LOS, and SES.

Conclusions:

An increase in hospital admissions for asthma and COPD were seen during November’s high wildfire months in 2018 and 2019 compared to low fire season Novembers in 2020 and 2021, yet not statistically significant. However, pediatric asthma patients did have a statistically significant increase in hospitalizations during these high wildfire months compared to the low season months. Interventions to prevent such hospitalizations, such as wildfire preparedness education and asthma or COPD action plan implementation, should be considered for those living in regions where wildfires have become seasonal normals.