Common effect measures in medical and economic studies? Results of an exploratory survey of physicians

Background: In economic evaluation studies quality-adjusted life years (QAL Ys) are often used as measure of effects. QALYs are calculated by weighting survival time with a valuation of health-related quality of life (HRQoL). The results may support clinical decisions for patient groups provided that physicians consider QALYs acceptable and clinically relevant. This study i nvestigates whether physicians accept the various methodological steps of t he calculation of QALYs and whether effect measures that result from these steps are useful in clinical studies, too. Methods: In summer 1998, 41 physicians (21 principal investigators of clini cal studies in oncology, 12 surgeons, 8 primary care physicians) completed a questionnaire. Results: 90% of the physicians considered HRQoL a relevant measure of clini cal effectiveness but only 54% were familiar with the concept of HRQoL. 80% accepted the creation of an index of HRQoL, 68% accepted the integration o f HRQoL and survival time into a single effect measure, but only 44% accept ed the multiplicative way of calculating QALYs. According to most physician s, HRQoL should be valued either by study patients or health care professio nals rather than general population samples. 92% of the physicians consider ed identical effect measures in clinical and economic studies necessary or desirable. Conclusions: QALYs are trot generally rejected by the responding physicians . The integration of HRQoL is largely accepted. The multiplicative way of c ombining survival time and HRQoL values is rejected by many physicians. The findings can be used to define a starting point for the development of com mon effect measures in medicine and health economics.