Increase in socioeconomic inequalities in mortality in a Southern European region: a small-area ecological study

This study sought to describe the total mortality trend by socioeconomic deprivation (SED) in the Madrid Autonomous Region, by sex and age group.

Cross-sectional ecological study by census tract, in two periods: 1994-2000 (P1) with SED of 1996 census and 2001-07 (P2) with SED of 2001 census. We calculated the relative risks (RRs) and their 95% credibility intervals (95% CIs) by SED quintile (Q), taking the quintile of least deprivation as reference. Besag-York-Mollié ecological regression models and the Integrated Nested Laplace Approximation procedure were applied. The absolute differences in age-standardized rates were compared by SED quintile.

Inequalities decreased in young adults: among men aged 20-39 years, the RR in Q5 versus Q1 ranged from 2.73 (95% CI, 2.51-3.02) in P1 to 1.93 (95% CI, 1.76-2.15) in P2, due to the greater improvement in the most underprivileged groups. In contrast, there was an increase in SED-related mortality in the 40-79 age group. Among men aged 40-59 years, the RR in Q5 versus Q1 rose from 1.88 (95% CI, 1.76-2.02) in P1 to 2.29 (95% CI, 2.17-2.43) in P2; the improvement was greater in the most privileged groups.

In a context of an economic boom, inequalities were observed to increase among adults by a greater improvement in the most privileged groups.