Gent, Belgium – Pain, anxiety, and functional or social limitations can cause an impaired Health-Related Quality of Life (HRQoL) in heart patients. Several measures exist to assess HRQoL, with some of them, such as the EQ-5D and the SF-6D (derived from the SF-12), generating a single utility measure of health. These are particularly useful in the calculation of cost-effectiveness ratio’s (ICER), for computing health benefits expressed in quality adjusted life years (QALYs).
The utility outcomes differ depending on the tool used. Whereas the main disadvantage of the EQ-5D is its ceiling effect, the potential advantages of SF-12 might disappear when converting the outcomes into an SF-6D utility score, due to the small differences between patients.
Researchers from Ghent University investigated how the HRQoL measure affects the outcome. Both EQ-5D and SF-12 outcomes in a sample of 7472 coronary patients from 20 European countries (the EUROASPIRE III survey: European survey of cardiovascular disease prevention and diabetes) were compared.
In their study, “EQ-5D Versus SF-12 in Coronary Patients: Are They Interchangeable?” published in Value in Health, the researchers found that although the EQ-5D and SF-6D are significantly correlated, large differences between the two instruments were observed. The median utility values differed significantly from each other with lower SF-6D outcomes compared to the EQ-5D results across all countries. In contrast to the SF-6D, an important ceiling effect was found on the EQ-5D instrument. Especially the mental component does not seem to be adequately captured by the EQ-5D instrument. Furthermore, patients with worse EQ-5D outcomes were more likely to have better SF-6D results, whereas patients with better EQ-5D outcomes were more likely to have worse SF-6D results.
Delphine De Smedt, MSc, from Ghent University, lead author on the study, states, “The way you measure HRQoL drives the results. EQ-5D and SF-6D utility estimates in coronary patients are not interchangeable. Awareness concerning this issue should be raised among researchers performing cost-effectiveness analyses.”
Value in Health (ISSN 1098-3015) publishes papers, concepts, and ideas that advance the field of pharmacoeconomics and outcomes research as well as policy papers to help health care leaders make evidence-based decisions. The journal is published bi-monthly and has over 8,000 subscribers (clinicians, decision makers, and researchers worldwide).
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