Household Income, Life Expectancy and Cause Specific Mortality in Norway, 2005-2015

Abstract

Abstract Background Examining causes of death and making comparisons across countries may increase understanding of the income-related differences in life expectancy. We describe income-related differences in life expectancy and causes of death in Norway and compare with US estimates. Methods A registry-based study including all Norwegian residents above age 40 between 2005 and 2015. Exposure was household income adjusted for household size and outcomes were life expectancy at age 40 and cause specific mortality. Results 3 041 828 persons contributed 25 805 277 person years and 441 768 deaths in the study period (mean age: 59.3 (SD, 13.6). Life expectancy was highest for women with the top 1% income at 86.4 (95% CI, 85.7 to 87.1) years, 8.4 (95% CI, 7.2 to 9.6) years longer than women in the lowest 1% income. Men with the lowest 1% income had the lowest life expectancy at 70.6 years (95% CI, 69.6 to 71.6), 13.8 years (95% CI, 12.3 to 15.2) less than men with the top 1% income. From 2005 - 2015, the differences in life expectancy by income increased, largely attributable to deaths from cardiovascular disease, cancers, COPD and dementia in older age groups and substance use deaths and suicides in the younger. Over the same period, women in the top income quartile gained 3.2 years (95% CI, 2.7 to 3.7), while life expectancy for women in the lowest income quartile was reduced by 0.4 years (95% CI, -1.0 to 0.2). For men, the top quartile gained 3.1 years (95% CI, 2.5 to 3.7) and the bottom gained 0.9 years (95% CI, 0.2 to 1.6). Differences in life expectancy by income levels in Norway were similar to those observed in the United States, but life expectancy was higher in Norway in the lower to middle part of the income distribution. Conclusions In Norway, there were substantial and increasing gaps in life expectancy by income from 2005 - 2015. The largest differences in life expectancy between Norway and US were for people in the lower to middle part of the income distribution. Key messages In Norway, a country with a largely tax financed universal health care system and moderate income differences, life expectancy by income are substantial and have increased between 2005 and 2015. The largest differences in life expectancy between Norway and US were for people in the lower to middle part of the income distribution.