title: Acute effects of ambient ozone on mortality in Europe and North America: results from the APHENA study.
abstract: The "Air Pollution and Health: A Combined European and North American Approach" (APHENA) project is a collaborative analysis of multi-city time-series data on the association between air pollution and adverse health outcomes. The main objective of APHENA was to examine the coherence of findings of time-series studies relating short-term fluctuations in air pollution levels to mortality and morbidity in 125 cities in Europe, the US, and Canada. Multi-city time-series analysis was conducted using a two-stage approach. We used Poisson regression models controlling for overdispersion with either penalized or natural splines to adjust for seasonality. Hierarchical models were used to obtain an overall estimate of excess mortality associated with ozone and to assess potential effect modification. Potential effect modifiers were city-level characteristics related to exposure to other ambient air pollutants, weather, socioeconomic status, and the vulnerability of the population. Regionally pooled risk estimates from Europe and the US were similar; those from Canada were substantially higher. The pooled estimated excess relative risk associated with a 10 µg/m3increase in 1 h daily maximum O3was 0.26 % (95 % CI, 0.15 %, 0.37 %). Across regions, there was little consistent indication of effect modification by age or other effect modifiers considered in the analysis. The findings from APHENA on the effects of O3on mortality in the general population were comparable with previously reported results and relatively robust to the method of data analysis. Overall, there was no indication of strong effect modification by age or ecologic variables considered in the analysis.
authors.affiliation: Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St, Baltimore, MD 21205, USA.
authors.forename: Roger D
authors.initials: RD
authors.lastname: Peng
authors.forename: Evangelia
authors.initials: E
authors.lastname: Samoli
authors.forename: Luu
authors.initials: L
authors.lastname: Pham
authors.forename: Francesca
authors.initials: F
authors.lastname: Dominici
authors.forename: Giota
authors.initials: G
authors.lastname: Touloumi
authors.forename: Tim
authors.initials: T
authors.lastname: Ramsay
authors.forename: Richard T
authors.initials: RT
authors.lastname: Burnett
authors.forename: Daniel
authors.initials: D
authors.lastname: Krewski
authors.forename: Alain
authors.initials: A
authors.lastname: Le Tertre
authors.forename: Aaron
authors.initials: A
authors.lastname: Cohen
authors.forename: Richard W
authors.initials: RW
authors.lastname: Atkinson
authors.forename: H Ross
authors.initials: HR
authors.lastname: Anderson
authors.forename: Klea
authors.initials: K
authors.lastname: Katsouyanni
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Samet
keywords: Cardiovascular; Mortality; Multi-city; Ozone; Respiratory; Time-series