Validation of the EuroQol questionnaire in cardiac rehabilitation

Objective: To analyse the psychometric properties of the EuroQol questionnaire (EQ-5D) applied to patients with acute coronary syndromes (ACS). Setting: Rehabilitation hospital. Patients and design: 106 consecutive patients with ACS (51% myocardial infarction, 42% coronary artery bypass grafting, 7% angina) completed the EQ-5D, the 36 item short form health survey (SF-36), and the MacNew questionnaire at admission, at discharge, and three months after inpatient cardiac rehabilitation. Acceptance, validity, reliability, and responsiveness of the EQ-5D were tested. Results: The EQ-5D was highly accepted. The EQ-5D index showed substantial ceiling effects after rehabilitation. As expected the EQ- 5D visual analogue scale (VAS) score (70.3 v 57.1) and EQ-5D index (77.8 v 64.5) were significantly better for patients with myocardial infarction than for patients who underwent surgery (both p <= 0.001). Significant correlations were found between the EQ-5D VAS score, EQ-5D index, and domains of the SF-36 (r = 0.21 to r = 0.74). The correlation with the MacNew subscores and with the global score ranged between 0.55 and 0.78. With repeated measurement the EQ-5D showed reasonable reliability in stable patients with intraclass correlation ranging between 0.91 and 0.54. EQ-5D was responsive in patients who indicated improvement in health states between admission and discharge (effect size 0.74 - 0.82). Conclusion: The psychometric properties of the EQ-5D were satisfying. It is a reasonably valid, reliable, and responsive instrument for patients with ACS. It may be useful in clinical research and epidemiological studies to generate preference based valuations of health related quality life.