Chronic obstructive pulmonary disease (COPD) is a common lung condition most often caused by smoking. COPD patients are at risk of severe episodes of deterioration - 'exacerbations'. Exacerbations are the second commonest cause of adult emergency medical hospital admission in the UK and are associated with shortened lives and decreased quality of life. Changes in temperature, humidity and air pollution are related to exacerbations, but these are not well characterised due, in part, to insufficiently detailed environmental exposure estimates in studies. This study will investigate the role of environmental factors such as pollution and temperature on exacerbations in COPD. This information will be of benefit to both patients and health care providers by helping to improve the organisation of health care resources, particularly in the winter and highlight times when patients should be aware of increased risk of exacerbations.
To find evidence supporting the hypothesis that increased levels of common atmospheric pollutants or falls/rises in temperature cause an increased risk and hence incidence of execerbations of COPD.
We will link patient data via General Practices contributing to CPRD to relevant atmospheric data held by DEFRA and BADC. As the best available proxy for environmental data in the locality of a given practice we will use data from the nearest monitoring station, found by translating post codes into British National Grid coordinates.
3. Data analysis
Poisson regression will be used to model the incidence and the relative risk of the occurrence of exacerbations of COPD using as explanatory variables the levels of pollutants, temperature and any relevant medical explanatory variables.
Health Outcomes to be Measured:
HES Admitted;ONS;Patient IMD;Practice IMD (Standard)