Contribution of causes of death to changing inequalities in life expectancy by income in Finland, 1997–2020

Background
Socioeconomic inequalities in mortality originate from different causes of death. Alcohol-related and smoking-related deaths are major drivers of mortality inequalities across Europe. In Finland, the turn from widening to narrowing mortality disparities by income in the early 2010s was largely attributable to these causes of death. However, little is known about recent inequalities in life expectancy (LE) and lifespan variation.

Methods
We used individual-level total population register-based data with annual information on disposable household income and cause-specific mortality for ages 30–95+, and assessed the contribution of smoking on mortality using the Preston-Glei-Wilmoth method. We calculated trends in LE at age 30 and SD in lifespan by income quintile in 1997–2020 and conducted age and cause-of-death decompositions of changes in LE.

Results
Disparity in LE and lifespan variation by income increased in 2015–2020, largely attributable to the stagnation of both measures in the lowest income quintile. The LE gap between the extreme quintiles in 2018–2020 was 11.2 (men) and 5.9 (women) years, of which roughly 40% was attributable to alcohol and smoking. However, the recent widening of the gap and the stagnation in LE in the lowest quintile over time were not driven by any specific cause-of-death group.

Conclusions
After a decade of narrowing inequalities in LE and lifespan variation in Finland, the gaps between income groups are growing again. Increasing LE disparity and stagnating mortality on the lowest income levels are no longer attributable to smoking and alcohol-related deaths but are more comprehensive, originating from most cause-of-death groups.