Proxies for healthcare need among populations: validation of alternatives--a study in Quebec.

STUDY OBJECTIVE: To compare the use of a non-mortality based proxy for relative needs for healthcare among regional populations with a mortality based proxy for population relative needs and to evaluate the additional value of a proxy based on a combination of non-mortality and mortality based proxies. DESIGN: Analysis of cross sectional data on mortality, socioeconomic status, and self assessments of health taken from registrar general records, a population census, and a population health survey. SETTING: The province of Quebec, Canada. COVERAGE: The populations of the 15 health regions in Quebec. MAIN OUTCOME MEASURE: The levels of correlation of indicators based on mortality data, socioeconomic data, and combined data with a standardised indicator of self assessed health. RESULTS: Variations in scores of a proxy based on socioeconomic data among regions explain 37% of the observed variation in self assessed health, 4% more than the level of variation explained by the standardised mortality rate scores. A weighted combination of both mortality and socioeconomic based proxies explains 56% of variation in self assessed health. CONCLUSIONS: Justification of "deprivation weights" reflecting variations in socioeconomic status among populations should be based on empirical support concerning the performance of such weights as proxies for relative levels of need among populations. The socioeconomic proxy developed in this study provides a closer correlation to the self assessed health of the populations under study than the mortality based proxy. The superior performance of the combined indicator suggests that the development of social deprivation indicators should be viewed as a complement to, as opposed to a substitute for, mortality based measures in needs based resource allocation exercises.