To establish the causal roles of environmental factors on exacerbations of COPD

Study type
Date of Approval
Study reference ID
Lay Summary

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.

Technical Summary

1. Objectives
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.

2. Methods
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.


Jennifer Quint - Chief Investigator - Imperial College London
Antonis Kousoulis - Collaborator - Mental Health Foundation
Liam Smeeth - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Miland Joshi - Collaborator - Imperial College London


HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation