Small area comparisons of health: applications for policy makers and challenges for researchers.

It is a challenge to researchers to present their results in a way that serves the needs of health policy makers. Small area maps of life expectancy provide an insightful presentation. In this study, we pursued small area comparisons on a scale that is smaller than is currently available on a province-wide basis. We visualized Nova Scotia's provincial variation in health and identified the Cape Breton Regional Municipality and Halifax's disadvantaged "North End" neighbourhood as areas with major health concerns. The observed health differences are only partially explained by socioeconomic factors such as income and unemployment. The study also demonstrated the feasibility of small area comparisons at the level of census consolidated subdivisions and neighbourhoods. There are various methodological challenges for researchers, however: allocation procedures such as the postal code-conversion-file may introduce substantial error; the application of appropriate spatial smoothing procedures is crucial to the interpretation of regional variation in health; and the migration of frail individuals to nursing homes affects the geographic variation in health.