Generic preference-based measures for low back pain

Study Design. Systematic review. Objective. This systematic review examines validity and responsiveness of three generic preference-based measures in patients with low back pain (LBP). Summary of Background Data. LBP is a very common incapacitating disease with a significant impact on health-related quality of life (HRQoL). Health state utility values can be derived from various preference-based HRQoL instruments, and among them the most widely ones are EuroQol 5 dimensions (EQ-5D), Short Form 6 Dimensions (SF-6D), and Health Utilities Index 3 (HUI III). The ability of these instruments to reflect HRQoL has been tested in various contexts, but never for LBP populations. Methods. A systematic search on electronic literature databases was undertaken to identify studies of patients with LBP where health state utility values were reported. Records were screened using a set of predefined eligibility criteria. Data on validity (correlations and known group methods) and responsiveness (effect sizes, standardized response means, tests of statistical significance) of instruments were extracted using a customized extraction template, and assessed using predefined criteria. Results. There were substantial variations in the 37 included papers identified in relation to study design and outcome measures used. EQ-5D demonstrated good convergent validity, as it was able to distinguish between known groups. EQ-5D was also able to capture changes of health states as results of different interventions. Evidence for SF-6D and HUI III was limited to allow an appropriate evaluation. Conclusion. EQ-5D performs well in LBP population and its scores seem to be suitable for economic evaluation of LBP interventions. However, the paucity of information on the other instruments makes it impossible to determine its relative validity and responsiveness compared with them.