Socioeconomic gradient in health in Canada: Is the gap widening or narrowing?

Background Notwithstanding a general improvement in health status, the socioeconomic gradient in health remains a public health challenge worldwide. Objective Using longitudinal data from the National Population Health Survey (NPHS, n = 17,276), we examined trends in socioeconomic gradients in two health indicators, viz. the Health Utility Index (HUI) and the Frailty Index (FI), among Canadian adults (25 years and older) between 1998/9–2010/11. Methods The relative and slope indices of inequality (RII and SII, respectively) were employed to summarize income- and education-based inequality in the FI and the HUI in Canada as whole, and in five regions: the Atlantic provinces, Quebec, Ontario, the Prairies and British Columbia. Results We found that education- and income-related inequalities in health were present in all five regions of Canada. The estimated RIIs and SIIs suggested that education-related inequalities in the FI and the HUI increased among women. The results also revealed that relative and absolute income-related inequalities in the HUI increased in Canada, especially among women. Both absolute and relative inequalities indicated that income-related inequalities in the HUI increased in Quebec and in the Prairies over time. Conclusion Persistent and growing socioeconomic inequalities in health in Canada over the past one and half decades should warrant more attention. The mechanisms underlying socioeconomic-related inequalities in Canada are less clear. Therefore, further studies are required to identify effective polices to reduce the socioeconomic gradient in health in Canada.