Trends in socioeconomic disparities in health care quality in four countries.

OBJECTIVE: To provide a targeted portrait of socioeconomic disparities in health care quality in four countries and how those disparities have changed over time.
DESIGN: Within each country, comparisons between the highest and lowest quintiles of socioeconomic status were made to determine if disparities exist and if any observed disparities have been decreasing over a 5-year period.
SETTING: Small geographic areas in Canada, England, New Zealand and the United States. DATA SOURCES: Data were obtained by working with national health statistics agencies in each country.
RESULTS: There were socioeconomic disparities in health care quality and health status for most of the indicators studied in all four countries. The analysis included nine quality indicators in four countries, for a total of thirty-six observations. Twenty-six observations had a ratio of highest to lowest socioeconomic quintile of <0.95 or >1.05. These disparities generally persisted over time. The relative difference between the highest and lowest quintile decreased over time in eight of the twenty-one observations with time-series data available.
CONCLUSION: The fact that disparities in a variety of indicators exist in four very different health systems underscores the importance of factors common to the four systems or factors outside the health system. Some successful strategies for reducing disparities could potentially be learned from the few examples of success in these countries.