Chronic obstructive pulmonary disease and comorbidities: a large cross-sectional study in primary care

Background: Chronic obstructive pulmonary disease (COPD) is common, and a major cause of morbidity and mortality worldwide. Recent studies suggest that comorbidities of COPD increase the risk of hospitalisation, polypharmacy, and mortality, but their estimated prevalence varies widely in the literature.

Aim: To evaluate the prevalence of 38 physical and mental health comorbidities in people with COPD, and compare findings with those for people without COPD in a large nationally representative dataset.

Design and setting: A cross-sectional data analysis on 1 272 685 adults in Scotland from 314 primary care practices.

Method: Data on COPD, along with 31 physical and seven mental health comorbidities, were extracted. The prevalence of comorbidities was compared between people who did, and did not, have COPD, standardised by age, sex, and socioeconomic deprivation.

Results: From the total sample, 51 928 patients had COPD (4.1%). Of these, 86.0% had at least one comorbidity, compared with 48.9% of people without COPD. Of those with COPD, 22.3% had ≥5 comorbid conditions compared with 4.9% of those who did not have COPD (adjusted odds ratio 2.63, 95% confidence interval = 2.56 to 2.70). In total, 29 of the 31 physical conditions and six of the seven mental health conditions were statistically significantly more prevalent in people who had COPD than those who did not.

Conclusion: Patients with COPD have extensive associated comorbidities. There is a real need for guidelines and health care to reflect this complexity, including how to detect those common comorbidities that relate to both physical and mental health, and how best to manage them. Primary care, which is unique in terms of offering expert generalist care, is best placed to provide this integrated approach.