Background Studies have linked ambient air pollution to chronic obstructive pulmonary disease (COPD) healthcare encounters. However, the association between air quality and rescue medication use is unknown.
Objectives We assessed the role of air pollution exposure for increased short-acting beta-2-agonist (SABA) use in patients with COPD through use of remote monitoring technology.
Methods Participants received a portable electronic inhaler sensor to record the date, time and location for SABA use over a 3-month period. Ambient air pollution data and meteorological data were collected from a centrally located federal monitoring station. Mixed-effects Poisson regression was used to examine the association of daily inhaler use with pollutant levels. Four criteria pollutants (PM2.5, PM10, O3 and NO2), two particulate matter species (elemental carbon (EC) and organic carbon), estimated coarse fraction of PM10 (PM10–2.5) and four multipollutant air quality measures were each examined separately, adjusting for covariates that passed a false discovery rate (FDR) screening.
Results We enrolled 35 patients with COPD (94.3% male and mean age: 66.5±8.5) with a mean forced expiratory volume in 1 s (FEV1) % predicted of 44.9+17.2. Participants had a median of 92 observation days (range 52–109). Participants’ average SABA inhaler use ranged from 0.4 to 13.1 puffs/day (median 2.8). Controlling for supplemental oxygen use, long-acting anticholinergic use, modified Medical Research Council Dyspnoea Scale and influenza season, an IQR increase in PM10 concentration (8.0 µg/m3) was associated with a 6.6% increase in daily puffs (95% CI 3.5% to 9.9%; FDR <0.001). NO2 and EC concentration were also significantly associated with inhaler use (3.9% and 2.9% per IQR increase, respectively).
Conclusions Exposure to increased ambient air pollution were associated with a significant increase in SABA use for patients with COPD residing in a low-pollution area.
- clinical medicine
- air pollution
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Contributors VSF and SM conceived of the study; ERL led data collection; APO and ERL led data analyses; and SM was responsible for primary manuscript writing. All authors contributed to interpretation of results and writing and gave final approval for the manuscript.
Funding This work was supported by VA Health Services Research and Development (HSR&D) Pilot Study PPO #10-299 from the US Department of Veterans Affairs HSR&D Program (PI: VSF). Additional support was provided by the Colorado School of Public Health at Colorado State University Faculty Pilot Grant Program (PI: SM).
Disclaimer The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of the Department of Veterans Affairs or the United States Government.
Competing interests None declared.
Patient consent Obtained.
Ethics approval VA Puget Sound Health Care System, VA Eastern Colorado Health Care System.
Provenance and peer review Not commissioned; externally peer reviewed.
Presented at Part of the research in this manuscript was presented in an abstract form at the Annual American Thoracic Society Meeting in 2017.
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