Investigation of Air Pollution and Cardiovascular Disease in a Population-Based Cohort

Abstract

ISEE-712 Objective: As part of the Border Air Quality Study, we used Canada's universal healthcare administrative databases to assess the relationship between air pollution and cardiovascular disease (CVD). We investigated the relationship between air pollution and CVD among groups with predisposing medical conditions and high-risk populations. Materials and Methods: The cohort includes all Greater Vancouver Regional District residents, 45 to 84 years of age as of January 1, 1999, who lived there since January 1, 1994. Predisposing conditions were monitored from January 1, 1994 to December 31, 1998. Hospitalization and outpatient physician visit records were used to obtain information on clinical diagnoses for each individual. Six-digit residential postal codes were used to assign exposure. Outcomes of interest included acute coronary syndrome (ACS, ICD-9:410, 411), chronic coronary syndrome (CCS, ICD-9:413, 414, 429.2), hypertension (HTN, ICD-9:401-405), congestive heart failure (CHF, ICD-9:428), diabetes (DM, ICD-9:250). Neighborhoods socioeconomic status (SES) was obtained from the 1996 and 2001 Census. Results: The cohort consisted of 559,110 subjects and was followed until December 2003. Cumulative prevalence 1994–1998 for ACS, CCS, CHF, HTN, and DM were 29.8, 78.9, 13.8, 228.5, and 79.6 per 1000 people. Incidences in 1999 for these outcomes were 6.2, 12.5, 5.0, 27.7, and 10.5 per 1000 people. Age, gender, and SES were considered as potential confounders. Exposures were measured as mean monthly concentrations based on inverse distance weighting of hourly ambient monitoring data (CO, NO, NO2, PM10, PM2.5, O3, SO2) and were also estimated for NO, NO2, PM2.5, black carbon, and wood smoke using land use regression models. Analyses will be conducted using Poisson regression. Conclusions: This large cohort will allow us to examine the relationship between air pollution and CVD among various subpopulations, while controlling for potential confounders at the individual level.