Effect of Health-Related Quality-Of-Life Instrument and Quality-Adjusted Life Year Calculation Method on the Number of Life Years Gained in the Critical Care Setting

Objectives: Health-related quality of life (HRQoL) and quality-adjusted life-years (QALYs) gained are basic elements in the cost-utility evaluations of health care. Different HRQoL instruments produce different scores for the same patient, and thus also a different number of QALYs. We examined the effect of these factors on the number of QALYs gained and the cost per QALY in the critical care setting. Methods: In 937 patients having been treated in the critical care setting in the Helsinki University Central Hospital the HRQoL scores were measured by the EQ-5D and 15D 6 and 12 months after start of treatment, and QALYs were calculated using four different sets of assumptions regarding recovery from disease. Results: The mean number of QALYs gained during the first year after treatment ranged from 0.178 +/- 0.206 to 0.550 +/- 0.508 and the consequent cost per QALY from (sic)38,405 to (sic)118,668 depending on HRQoL instrument and assumptions used in the calculations regarding recovery from disease. Conclusions: The HRQoL instrument and the assumptions employed regarding recovery from disease have a great influence on the results of cost-utility analyses and should, therefore, be explicitly described in studies reporting QALYs. Furthermore, a common consensus on which calculation method should be used within critical care would be urgently needed.