Short-term effects of multiple outdoor environmental factors on risk of asthma exacerbations: Age-stratified time-series analysis

• Published in: Journal of allergy and clinical immunology Vol. 144; no. 6; pp. 1542 - 1550.e1
• Main Authors: Lee, Seung Won, Yon, Dong Keon, James, Chase C., Lee, Shinhae, Koh, Hyun Yong, Sheen, Youn Ho, Oh, Jae-Won, Han, Man Yong, Sugihara, George
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.2019; Elsevier Limited
• Subjects: aeroallergen; Age; air pollutant; Air pollution; Allergens; Asthma; Asthma exacerbation; Carbon monoxide; Children; Diurnal; Emergency medical services; Environmental effects; Environmental factors; Epidemics; Geriatrics; Health risks; human rhinovirus; Humidity; Infants; Infections; Influenza; influenza virus; Nitrogen dioxide; Particulate matter; Pollen; Pollutants; Population; Respiratory syncytial virus; Rhinovirus; Risk factors; Sensitivity analysis; Statistical analysis; Sulfur; Sulfur dioxide; Time series; Trees; Variables; Viruses; weather condition; RR; SS; DTR; ICD-10; AE; O3; DLNM; weather condition; CO; Asthma exacerbation; HRV; aeroallergen; NO2; human rhinovirus; RSV; SO2; influenza virus; IFV; PM10; air pollutant
• ISSN: 0091-6749; 1097-6825
• DOI: 10.1016/j.jaci.2019.08.037

Although the different age groups had differences in sensitivity of asthma exacerbations (AEs) to environmental factors, no comprehensive study has examined the age-stratified effects of environmental factors on AEs. We sought to examine the short-term effects in age-stratified groups (infants, preschool children, school-aged children, adults, and the elderly) of outdoor environmental factors (air pollutants, weather conditions, aeroallergens, and respiratory viral epidemics) on AEs. We performed an age-stratified analysis of the short-term effects of 4 groups of outdoor environmental factors on AEs in Seoul Metropolitan City (Korea) from 2008 and 2012. The statistical analysis used a Poisson generalized linear regression model, with a distributed lag nonlinear model for identification of lagged and nonlinear effects and convergent cross-mapping for identification of causal associations. Analysis of the total population (n = 10,233,519) indicated there were 28,824 AE events requiring admission to an emergency department during the study period. Diurnal temperature range had significant effects in pediatric (infants, preschool children, and school-aged children) and elderly (relative risk [RR], 1.056-1.078 and 1.016, respectively) subjects. Tree and weed pollen, human rhinovirus, and influenza virus had significant effects in school-aged children (RR, 1.014, 1.040, 1.042, and 1.038, respectively). Tree pollen and influenza virus had significant effects in adults (RR, 1.026 and 1.044, respectively). Outdoor air pollutants (particulate matter of ≤10 μm in diameter, nitrogen dioxide, ozone, carbon monoxide, and sulfur dioxide) had significant short-term effects in all age groups (except for carbon monoxide and sulfur dioxide in infants). These findings provide a need for the development of tailored strategies to prevent AE events in different age groups. [Display omitted]