Gestational and postnatal exposure to wildfire smoke and prolonged use of respiratory medications in early life

Objective: Examine the association of gestational and postnatal exposure to wildfire smoke on prolonged use of prescription medication for respiratory conditions in early life. Methods: We used MarketScan claims data to create cohorts of term children born in western United States between Jan 1, 2010 and Dec 31, 2014 who were included for at least one year or at least three years after three exposure periods. Exposure periods were gestational (280-197[T1], 196-99[T2], and 98-1[T3] days before birth) and postnatal periods (1-84[PN1] and 85-168[PN2] days post birth). Using the NOAA Hazard Mapping System at the Metropolitan Statistical Area (MSA) level, wildfire smoke exposure was quantified as average weekly number of smoke days within each exposure period, based on residential MSA at birth. Prolonged use (≥30 days; PU) of respiratory medications was assigned based on indication (upper respiratory, lower respiratory, any respiratory conditions) with additional assessment for multiple prolonged uses (2+ prolonged uses; MPU). We used logistic regression models with random intercepts for MSAs adjusted for child sex, birth season, and birth year to estimate odds ratios (OR) and associated 95% confidence intervals (CI) for PU and MPU per 1-day increase in average weekly smoke days exposure. We used likelihood ratio tests (LRT) to examine sex-specific associations. Results: Smoke exposure during PN1 was positively associated with MPUs of any medications, as well as lower respiratory medications in both 1-yr and 3-yr cohorts. Notably, in the 3-yr cohort there were sex specific associations between PN1 exposure and PU of any respiratory medication (LRT p = 0.02), with females exhibiting a more positive response than males (female OR: 1.04 (95%CI 0.88, 1.23); male OR: 0.88 (95%CI 0.76, 1.02)). Conclusion: We observed associations between gestational and postnatal smoke exposure and multiple prolonged uses of respiratory medications, differential on exposure period and sex. 

Impact/Purpose

To examine the association of gestational and postnatal exposure to wildfire smoke on prolonged use of prescription medication for respiratory conditions in early life.

Citation

Jardel, H., K. Rappazzo, T. Luben, C. Keeler, B. Staley, C. Ward-Caviness, M. Rebuli, Y. Xi, M. Hernandez, A. Chelminski, I. jaspers, A. Rappold, AND R. Dhingra. Gestational and postnatal exposure to wildfire smoke and prolonged use of respiratory medications in early life. International Society for Environmental Epidemiology ¿ North American Chapter Conference 2023, Corvallis, OR, June 19 - 21, 2023.