Using lifespan variation to better understand long-term trends in health inequalities in Scotland and Europe

Cross-country comparisons of socioeconomic inequalities in mortality/life expectancy (LE) face limitations regarding the comparability of population subgroup data. One potential alternative which can overcome this limitation is lifespan variation (LV). Our aims were to: (i) compare long-term trends in LV across Western European countries, focussing on Scotland as a country with known wide LE inequalities; and (ii) explore the validity of LV through comparisons with ranked measures of socioeconomic inequalities in mortality/LE within Scotland. We calculated e† (one measure of LV) using Human Mortality Database data from 1855 to 2021 for European nations, by sex. We then compared e† with absolute inequalities in mortality and LE by ranked area-level socioeconomic deprivation for all 32 local government areas in Scotland. Male and female LV in Scotland is the highest in Western Europe. For males especially, this resulted from increases in the 1980s-1990s, and was made worse by further increases in the early 2010s. All UK nations have relatively high LV, especially among females. Comparisons of sub-national, area-based, data show a moderate level of correlation between ranked LV and absolute socioeconomic inequalities in mortality (0.57), and male (0.48) and female (0.51) LE. For cross-country comparisons, LV may be a useful proxy for absolute socioeconomic inequalities in mortality/LE where comparable socioeconomic measures are not available; however, it requires cautious interpretation. Given the high level of, and recent increases in, LV in Scotland and the UK, the need for socioeconomic policies to narrow health inequalities has never been more urgent.