To compare in patients with inflammatory bowel disease the performance of a value set for the EQ-5D based on experienced health states (EHSs) with value sets based on given health states (GHSs).
A value set based on EHSs and valuation by the visual analogue scale (VAS) in the German general population was compared with a German and a UK value set, both based on GHSs and time-trade off valuation. Accuracy in the prediction of actual VAS ratings by patients was assessed using correlation and mean absolute error. Construct validity was tested by correlation with established disease activity indices and test-retest reliability by intraclass correlation between two measurements. Data originated from a survey of 270 patients with Crohn's disease and 232 patients with ulcerative colitis.
EHS-VAS correlates best with actual VAS ratings for all patients but not for all subgroups. EHS-VAS has the lowest mean absolute error for almost all analyzed groups except for measured differences between two time points. Regarding test-retest reliability in all patients, EHS-VAS correlations were closest to those of actual VAS ratings.
EHS-VAS renders experience-based valuations but not decision utilities. GHS-based approaches cover severe health states more extensively, but study patients reported health states similar to those of a general population. Compared to GHS time-trade off value sets, the EHS-VAS value set predicted EQ-5D VAS valuations by patients with inflammatory bowel disease equally well and partly better. It performed partly better with respect to test-retest reliability and the same with respect to construct validity.