Introduction: Past research has suggested significant relationships between symptoms and health outcomes among patients with COPD. However, these studies have generally focused on a broad COPD sample and may have included those not receiving proper treatment. As a result, the aim of this study was to document the burden of COPD symptoms among those who are currently treated with the standard-of-care (SOC) medications in both the US and Western Europe.
Methods: Data from the 2013 US (N=75,000) and 2011 (N=57,512)/2013 (N=62,000) European (France, Germany, Italy, Spain, and UK; 5EU) National Health and Wellness Survey (NHWS) were used. The NHWS is a health survey administered to a demographically representative sample of the adult population in each country. A total of 1,666 and 2,006 patients with self-reported physician diagnosis of COPD in the 5EU and US, respectively, were being treated with the appropriate SOC (based on self-reported medication use) and were included in the analyses. Symptoms (eg, dyspnea, coughing, wheezing) were reported descriptively and summed to create a symptom score (with higher score indicating more frequent symptoms). The relationships between the symptom score and patient outcomes (eg, health status using the Short Form-36 version 2 [SF-36v2], work productivity and activity impairment [WPAI], and self-reported health care resource use) were explored using regression modeling.
Results: Nearly all patients (99.7% and 99.8% in the 5EU and US, respectively) reported experiencing symptoms and >80% reported experiencing at least one symptom "often". Increasing symptom scores were associated with poorer health status (unstandardized beta [b] =-0.87 and -0.78 for mental component summary and physical component summary, respectively, in the US and b =-0.67 and -0.79 in the 5EU, respectively; all P<0.05). Increasing symptom scores were also associated with greater work impairment (b =0.09 and 0.06 for the US and 5EU, respectively), activity impairment (b =0.05 and 0.06, respectively), and health care resource utilization (eg, hospitalizations: b =0.05 and 0.06, respectively) (all P<0.05). Approximately 70% of patients reported some level of non-adherence. Greater non-adherence was significantly associated with more frequent symptoms, poorer health status, and greater work impairment and health care resource use (all P<0.05).
Conclusion: Patients with COPD who are using the appropriate SOC still experience symptoms, which have a significant effect on both humanistic and economic outcomes.
Keywords: COPD; adherence; health care resource use; quality of life; symptoms; work productivity.