Public Health Impact of Wildfire Smoke Exposure: Analysis of Respiratory-Related Medicaid Claims in Wyoming

TL;DR

Wildfire smoke leads to a significant delay in Medicaid claims for respiratory issues in Wyoming, likely due to healthcare access barriers.

Contribution

The study identifies a predictable lagged public health effect of wildfire smoke exposure, driven by suppressed demand and structural healthcare barriers.

Findings

Respiratory claims increased five-fold (from 1.6 to 7.9 per day) in the seven days after a wildfire smoke episode.

The claims surge is attributed to suppressed demand due to healthcare access barriers among Medicaid recipients.

The findings suggest a need for post-event healthcare preparedness rather than acute crisis response.

Abstract

Research question: Does the rate of respiratory claims in the seven days immediately following a wildfire smoke episode significantly exceed the claims rate during the acute exposure period? The hypothesis posits that structural barriers inherent to frontier healthcare suppress immediate claims demand, resulting in a predictable lagged effect.

Methods: Daily respiratory claims data were analyzed across 23 Wyoming counties during the 2012-2024 wildfire seasons. The primary analytical approach employed a negative binomial generalized mixed-effects model with county-level fixed effects to compare the incidence rate of claims during the smoke episode (the exposure period) with that during the subsequent seven-day post-episode period.

Results: The analysis revealed a statistically significant five-fold increase in respiratory claims (p < 0.001), with predicted mean daily claims rising from approximately 1.6 during smoke episodes to 7.9 in the subsequent seven-day period, with an incidence rate ratio of 5.02. Specifically, the claims rate in the seven days post-episode was higher in the negative binomial model than the rate observed during the actual exposure period. This finding confirms the existence of a highly predictable, delayed public health phenomenon.

Conclusion: The observed surge in claims is interpreted as the release of suppressed demand, driven by the intersection of particulate matter 2.5’s biological latency and the overwhelming structural barriers (e.g., urgent access, lack of transportation) faced by Medicaid recipients. This research supports consideration of a paradigm shift from acute crisis response to a lag-adjusted preparedness model, requiring public health systems to implement targeted post-occurrence outreach and proactive structural interventions to mitigate this preventable surge in post-event healthcare utilization.

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