Differences in patient characteristics and associations with comorbid load in Dutch and Australian patients

COPD frequently exists with comorbidities, but inclusion of COPD patients with severe comorbidities in self-management trials is still relatively uncommon.

In a randomised controlled self-management trial COPD patients with ≥ 1 comorbidity were included. We have explored possible differences in patient characteristics between a Dutch and Australian COPD sample, and evaluated associations between comorbid load and patient characteristics using multivariate logistic regression analyses.

In total 201 COPD patients (mean age 68.5 ± 8.9; 64.2% male) were included (Netherlands, n=145, Australia, n=56), and 42.3% had ≥ 2 comorbidities with no differences in comorbid load between both countries (p=0.29), although there were significant baseline differences (p<0.05): Australian patients had worse mMRC dyspnoea, lung function and COPD Assessment Test scores, a higher comorbid depression rate, reported less exercise/week, but had better cognitive function scores and health literacy. In the Dutch patients comorbid load was associated with worse health literacy (OR 2.84, 95% CI 1.37-6.67), less self-reported exercise/week (OR 1.06, 95% CI 1.01-1.12), and stronger fatigue experiences (OR 1.04, 95% CI 1.01-1.06). For the Australian patients it was associated with stronger emotional feelings (OR 2.86, 95% CI 1.43-5.88).

Despite similar inclusion criteria, differences in patient characteristics were observed between Dutch and Australian COPD patients. Comorbid load was associated with different patient characteristics per country. This highlights the need for individual assessments of COPD patients, so that self-management interventions can be tailored to patients' needs and capabilities.