There are major inequalities in life expectancy by income in both the US and Norway, according to a recent study conducted by the Norwegian Institute of Public Health in collaboration with the Institute For Health Metrics And Evaluation (IHME).
The researchers wanted to find out if life expectancy varies with income in Norway and whether the differences are comparable to those in the United States.
Average life expectancy among Norway’s one per cent richest was found to be 14 years higher for men and 8 years higher for women compared to the country’s one per cent poorest.
A total of 3,041,828 people contributed 25,805,277 person-years and 441,768 deaths during the study period. Life expectancy was found to be highest for women with income in the top 1% (86.4 years), while men with the lowest 1% income had the lowest life expectancy (70.6 years).
Between 2005 and 2015 the life expectancy gap between the richest and poorest in Norway widened and were comparable to those in the United States.
Over the ten year period, Norway’s richest 25 per cent of women increased life expectancy by 3.2 years while the poorest 25 per cent reduced life expectancy by 0.4 years. The richest 25 per cent men increased life expectancy by 3.1 years, while the poorest 25 per cent increased by just 0.9 years.
The researchers compared the Norwegian results with a similar study from the USA during the same period.
They found:
- Life expectancy was higher in Norway than in the USA across most of the income distribution, except for the very highest and very lowest income percentiles.
- The difference in life expectancy among the the richest one per cent of men and poorest men in the US is roughly the same as in Norway. However, the difference is smaller for Norwegian women compared to American women.
- From 2000-2014, poor Americans have had a significantly lower increase in life expectancy than rich Americans. The researchers observed the same tendency in Norway.
“It has surprised researchers and policy makers that even with a largely tax-funded public health care system and relatively evenly distributed income, there are substantial differences in life expectancy by income in Norway” says Dr Jonas Minet Kinge, senior researcher at the Norwegian Institute of Public Health and Associate Professor in Health Economics at the University of Oslo.
“We also observe important differences between the USA and Norway. Life expectancy was higher in Norway than in the USA across most of the income distribution, except for the very highest and very lowest income percentiles, in which life expectancies were similar in the two countries. The largest differences in life expectancy between the countries were seen for the lower to middle income men and women,” he added.
Kinge said that it is not well understood why the the differences in life expectancy are so great and why they are increasing.
“Studies from Sweden and other countries suggests that other factors besides money in itself explain why those with lower income have lower life expectancy,” Kinge said. “For example, those who have a low income live more often alone and often have a lower education. Furthermore, foetal life, upbringing and other environmental conditions can be important.”
“We need more research on the causes of the gradient. Fortunately, the research environment in Norway has the competence to link the health registries on an individual level with income, education and household information. Via such data merging we can perform more advanced analyses than most other countries, as this study also demonstrates,” he concluded.
Journal Citation
Jonas Minet Kinge, PhD; Jørgen Heibø Modalsli, PhD; Simon Øverland, PhD; et al
JAMA. Published online May 13, 2019. doi:10.1001/jama.2019.4329