Environmental factors and hospitalisation for COPD in a rural county of England
Background: Chronic Obstructive Pulmonary Disease (COPD) is a major global cause of morbidity and mortality. Studies in urban areas have shown associations between air pollutants and hospital admissions for COPD. We investigated if temporal variations in air quality are associated with hospital admissions for COPD in a rural region with lower concentrations of air pollutants than previously studied. Methods: Daily COPD admissions were recorded for patients attending 3 hospitals in the county of Norfolk, England, between January 2006 and February 2007. Records were combined with daily information on concentrations of 6 air pollutants (carbon monoxide, nitric oxide, nitrogen dioxide, oxides of nitrogen, ozone and fine particulates), airborne pollens, temperature, and influenza incidence. A case-crossover analysis was used to examine the association between air pollution and daily admissions. Results: There were 1,050 admissions for COPD over the study period. After adjustment for temperature, pollen and respiratory infections, each 10 ?g/m3 increase in CO was associated with a 2% percent increase in the odds of admission. Values of 17%, 22%, and 9% were observed for NO, NO2 and NOx respectively. No associations were observed with O3 or PM10. Conclusion: Amongst a population of a less urbanised area than previously investigated, this study found evidence that ambient pollutant concentrations were still associated with the risks of hospital admission for COPD.
Journal of Epidemiology and Community Health, 63, (4), 324-328