Background Non-respiratory symptoms in people with COPD are often under-recognized. We aimed to study a variety of (non-)respiratory symptoms in people with COPD and non-COPD controls and to explore the associations between symptom-based clusters and clinical characteristics.

Methods Characteristics were assessed in 538 people with COPD from primary, secondary, tertiary care and 116 non-COPD controls. Severity of 20 symptoms was measured using a Visual Analogue Scale (VAS), ranging from 0 (no symptom) to 100 mm (maximum severity) (Janssen et al. BMC Palliat Care 2008). K-means cluster analysis was applied on symptoms? severity in the patient sample.

Results Patients were comparable with controls in terms of gender (58% vs. 55% male, p=0.132) and age (64 [9] vs. 63 [6] yrs, p=0.552) and had a worse FEV₁ (57 [23]% vs. 111 [17]% pred, p<0.001). Patients had higher VAS scores for all symptoms (p<0.05). Three clusters were identified [fig 1A]. Health status and care dependency differed between all clusters, while physical mobility, exacerbation history and lung function differed between clusters 1 and 2 and clusters 1 and 3 (p<0.05) [fig 1B].

Conclusions People with COPD report a high symptom burden. Cluster analysis demonstrated co-occurrence of different symptoms highlighting the heterogeneity of symptom experience. Identifying clusters of patients with shared symptom experiences can help to understand the impact of the disease and define adequate treatment strategies.