An Exploratory Study of Alternative Time Frames and Descriptors for EQ-5D-5L in Obstructive Airway Diseases Using Mixed Methods.

Objectives: EQ-5D-5L with its recall time of "today" may limit its ability to capture episodic symptoms and exacerbations in chronic obstructive airway diseases (OAD). We examined whether longer time frames and changing the intensity response scales to frequency scales could improve the measurement properties of EQ-5D-5L.

Methods: We used a mixed-method design starting with in-depth interviews with 20 patients and clinicians to elicit preferred time frames using concept elicitation techniques and content analyses. We then administered the top 4 preferred variants using 1- and 4-weeks' time frames with the original intensity or an alternative frequency response scale alongside EQ-5D-5L and St George Respiratory Questionnaire to OAD patients during 2 different visits. We compared the ceiling effects and construct validity by testing a priori hypotheses in relation to St George Respiratory Questionnaire and clinical outcomes via correlation and receiver operating characteristic (ROC) analyses, respectively. Follow-up patients were categorized into "better," "stable," and "worse" groups to assess reliability using intraclass correlation coefficient (ICC) or Cohen's Kappa (k) and responsiveness using ROC analysis.

Results: A total of 184 patients (mean [SD] age: 54[18]; female: 37.0%) completed baseline assessments. A total of 120 patients also completed follow-up assessments (mean [SD] interval: 2.8 [1.7] months). The ceilings were lower in the variants compared with EQ-5D-5L (P < .001). Reliability of the variants were comparable to or higher than EQ-5D-5L. The c-statistic values derived from ROC analyses of the variants were consistently higher than EQ-5D-5L.

Conclusions: Use of longer time frames with the original intensity or the frequency response scales may improve EQ-5D-5L's psychometric properties in OAD patients.