title: Short-term outdoor temperature change and emergency department visits for asthma among children: a case-crossover study.
abstract: Although weather changes are known to cause asthma symptoms, their impact on asthma-related health-care utilization is poorly understood. The objective of the present study was to determine the association between short-term outdoor temperature change and asthma-related emergency department (ED) visits among children 3-18 years of age in Detroit, Michigan, in 2000-2001. Descriptive analyses of patient and ED visit characteristics were performed. A case-crossover study utilizing time-stratified controls was conducted to determine the impact of maximum temperature change and change rate measured during 4-, 8-, 12-, and 24-hour periods. Multivariable conditional logistic regression demonstrated the relation between ED visits and temperature change after controlling for other weather and pollutant measures. There were 4,804 asthma-related ED visits during the study period, and they occurred most frequently in the fall and during morning hours. The case-crossover study showed a statistically significant inverse relation between ED visits and maximum 24-hour temperature change after adjustment for climatic factors (for temperature change, odds ratio = 0.992, P = 0.04; for temperature change rate, odds ratio 0.972, P = 0.01). The association persisted after air pollutant measures were added to the model, although the association was not significant. Despite the finding that a greater 24-hour temperature change decreased the risk of asthma-related ED visits, the overall results suggested a negligible association with short-term temperature change.
authors.affiliation: Department of Epidemiology, School of Public Health and Tropical Medicine, Tulane University, New Orleans, Louisiana, USA. betsywasilevich@tulanealumni.net
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Wasilevich
authors.forename: Felicia
authors.initials: F
authors.lastname: Rabito
authors.forename: John
authors.initials: J
authors.lastname: Lefante
authors.forename: Eric
authors.initials: E
authors.lastname: Johnson
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000453:epidemiology* / Q000628:therapy; D002648:Child; D002675:Child, Preschool; D018592:Cross-Over Studies; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008824:Michigan / Q000453:epidemiology; D012621:Seasons; D013696:Temperature; D013997:Time Factors