A comparison of the ICECAP-O with EQ-5D in a falls prevention clinical setting: are they complements or substitutes?

PURPOSE: Our research explored whether two preference-based outcome measures (EuroQol EQ-5D and ICECAP-O) are complements or substitutes in the context of the Vancouver Falls Prevention Clinic for seniors.
METHODS: The EQ-5D and ICECAP-O were administered once at 12 months post first clinic attendance. We report descriptive statistics for all baseline characteristics collected at first clinic visit and primary outcomes of interest. We ascertain feasibility by reporting item completion rates for the EQ-5D and ICECAP-O. Contingency tables for a priori assertions between the ICECAP-O and EQ-5D were used to demonstrate whether unique or similar aspects of benefit were captured. We used exploratory factor analysis, to ascertain the number of unique underlying latent factors associated with the attributes assessed by the EQ-5D and ICECAP-O.
RESULTS: We report data on 215 seniors who attended the Vancouver Falls Prevention Clinic who had a mean age of 79.3 (6.2) years. The item completion rate was 99 % for the EQ-5D and 92 % for the ICECAP-O. The two contingency tables detailed few discrepancies. The results of the exploratory factor analysis indicate that the two instruments are tapping into distinct factors that are complementary.
CONCLUSION: Our study suggests that the EQ-5D and ICECAP-O provide complementary information.