Frequency of emergency room visits for childhood asthma in Ottawa, Canada: the role of weather

Abstract

The aim of this study was to evaluate associations between meteorological conditions and the number of emergency department visits for asthma in a children's hospital in Ottawa, Canada. A case-crossover study design was used. Hospital emergency department visits for asthma between 1992 and 2000 were identified based on patients' presenting complaints. We obtained hourly measures for the following meteorological variables: wind speed, temperature, atmospheric pressure, relative humidity, and visibility. Particular emphasis was placed on exploring the association between asthma visits and fog, thunderstorms, snow, and liquid and freezing forms of precipitation. In total, there were 18,970 asthma visits among children between 2 and 15 years of age. The number of visits and weather characteristics were grouped into 6 h case and control intervals. The occurrence of fog or liquid precipitation was associated with an increased number of asthma visits, while snow was associated with a reduced number (P<0.05). Stratified analyses by season found no association in any of the four calendar intervals between the number of asthma visits and visibility, change in relative humidity and change in temperature. In contrast, summertime thunderstorm activity was associated with an odds ratio of 1.35 (95% CI=1.02-1.77) relative to summer periods with no activity. Models that incorporate calendar and meteorological data may help emergency departments to more efficiently allocate resources needed to treat children presenting with respiratory distress.

A trans-disciplinary overview of case reports of thunderstorm-related asthma outbreaks and relapse

“…In Ottawa, Canada, hospital emergency department visits for asthma between 1992 and 2000 were identified and their relationships to fog, thunderstorms, snow, and liquid and freezing forms of precipitation were investigated. In total, there were 18,970 asthma visits among children aged 2-15 yrs and their occurrence was significantly associated with summer thunderstorm activity relative to summer periods with no activity (OR 1.35, 95% CI 1.02-1.77) [16]. In Atlanta, GA, USA, 24,350 emergency department asthma visits occurred on days following thunderstorms (out of 215,832 emergency department asthma visits during the study period) [17].…”

The Effects of Weather on the Incidence of Sudden Sensorineural Hearing Loss: A 5-Year Population-Based Study

“…A number of studies, including research on asthma attacks [Villeneuve et al, 2005], acute myocardial infarction [Kveton, 1991], the onset of rheumatoid arthritis [Patberg, 2003], hip fracture [Mirchandani et al, 2005] and bipolar disorder [Shapira et al, 2004], have also consistently confi rmed the association of these diseases with different climatic parameters. Nevertheless, the present study has failed to establish any signifi cant association between the weather and the incidence of SSNHL; we, therefore, conclude that the onset of SSNHL is independent of weather conditions.…”

Seasonality and Climatic Associations with Violent and Nonviolent Suicide: A Population-Based Study

“…A possible explanation for the discrepancy may be their use of multiple regression modeling, rather than SARIMA models used in the present study to adjust for time trend effects. SARIMA modeling is a state-of-theart statistical method that has been widely used to investigate the association between climate and disease incidence [30][31][32] . Given the reliance of past studies on univariate statistical methods including correlation analyses, it is understandable that they could not identify the key meteorological factor(s) driving the seasonal association because of high correlations between meteorological parameters in each season.…”