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

ObjectivesHealth-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.MethodsIn 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.ResultsThe 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 €38,405 to €118,668 depending on HRQoL instrument and assumptions used in the calculations regarding recovery from disease.ConclusionsThe 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.