The relationship between social mobility and mortality: analysis of intercensal data (1991, 2001, and 2011)

Persisting social disadvantage is associated with poor health and higher mortality. Increasing social mobility is, therefore, a major policy goal in the United Kingdom and other Western nations. However, the extent to which mortality is attenuated by upward social mobility is unclear, evidence from lifecourse studies suggests the persisting effects of early disadvantage. We sought to examine the relationship between intercensal social mobility and all-cause mortality. Census returns from three waves of the Northern Ireland Longitudinal Study (1991 n = 439 553; 2001 n = 446 573; 2011 n = 480 031) linked with mortality data. Using census data on 'educational attainment', 'occupational social class', 'housing tenure', and 'household car access' we derived an index of individual and household-level disadvantage and examined intercensal social mobility and all-cause mortality between 1991-2001 and 2001-2011. At each census point, all-cause mortality was positively associated with increasing social disadvantage. Relative to the least disadvantaged at each census, populations in the most disadvantaged areas recorded (hazard ratios = 3.23 (95% CI 2.49, 4.19); HR = 5.09 (4.21, 6.17), and HR = 5.30 (4.56, 6.16)) for 1991, 2001, and 2011, respectively. Compared with the socially static groups, those with generally downward social mobility showed an excess mortality, while mortality in the upwardly social mobility groups was generally lower than (or similar to) those in more socially static groups. Perhaps predictably, all-cause mortality was strongly associated with downward social mobility across time periods. Of greater concern, the Hazards associated with downward mobility appear to intensify over time. Moreover, increased social mobility appears to have little positive impact on mortality.