Patterns of Comorbidities in Newly Diagnosed COPD and Asthma in Primary Care

Study objectivesThere is increasing interest in the frequency and nature of comorbidities in patients with obstructive lung disease: COPD and asthma. We aimed to quantify baseline rates of comorbidities in COPD and asthma patients and to compare the risks to the general population.Design, setting, and participantsWithin the UK General Practice Research Database, we compared incident patients with COPD (n = 2,699) and asthma (n = 7,931) physician diagnosed in 1998 with age, gender, time, and practice-matched cohorts. Rates were calculated and relative risks (RRs) were estimated for comorbidities in major organ systems and selected medical events of a priori interest.Measurements and resultsIn both COPD and asthma, the total sum of diagnoses related to major organ systems was higher than in their matched population controls. Among incident COPD patients, a frequency > 1% within the first year after diagnosis was observed for angina, cataracts, bone fractures, osteoporosis, pneumonia, and respiratory infections, the highest being angina with 4.0%. Compared to the non-COPD cohort, COPD patients were at increased risk for pneumonia (relative risk [RR] = 16.0), osteoporosis (RR = 3.1), respiratory infection (RR = 2.2), myocardial infarction (RR = 1.7), angina (RR = 1.7), fractures (RR = 1.6), and glaucoma (RR = 1.3) [all p < 0.05]. Of note, 2.0% of COPD patients had cataracts recorded, but this rate was no different than that of the non-COPD cohort (RR = 0.9). Among incident asthma patients, the occurrence of events was generally lower, likely due to the younger age distribution, except for 4.0% with respiratory infection (RR = 1.84) and 1.7% with fractures (RR = 1.5). Angina prevalence was 0.7% in the asthma cohort and 1.4 times more common than in patients without asthma.ConclusionCOPD and asthma are conditions associated with many comorbidities, albeit asthma to a lesser extent than COPD, which had not been systematically reviewed before. Baseline rates of cardiovascular-, bone-, and other smoking-related conditions are high.