Clinically important changes in health-related quality of life for patients with chronic obstructive pulmonary disease: an expert consensus panel report

Without clinical input on what constitutes a significant change, health-related quality of life (HRQoL) measures are less likely to be adopted by clinicians for use in daily practice. Although standards can be determined empirically by within-person change studies based on patient self-reports, these anchor-based methods incorporate only the patients' perspectives of important HRQoL change, and do not reflect an informed clinical evaluation. The objective of this study was to establish clinically important difference standards from the physician's perspective for use of 2 HRQoL measures among patients with chronic obstructive pulmonary disease (COPD).

We assembled a 9-person expert panel of North American physicians familiar with the use of the Chronic Respiratory Questionnaire (CRQ), a disease-specific HRQoL measure, or the generic Medical Outcomes Study Short-Form 36-Item Health Survey (SF-36, Version 2.0) among patients with COPD.

Using 2 rounds of the Delphi process, 1 in-person meeting, and an iterative improvement process for circulating and correcting the final report, the expert panel established small, moderate, and large clinically important change levels for the CRQ and SF-36.

For this expert physician panel, levels for detecting clinically important differences on the CRQ were equal to or slightly higher than previous studies based on patient-reported differences. Clinically important differences on the SF-36, Version 2.0, were noticeably larger than previous estimates based on cross-sectional differences between clinically defined patient groups.