Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2016 Dec 23;6(12):e010974.
doi: 10.1136/bmjopen-2015-010974.

Shape of the association between income and mortality: a cohort study of Denmark, Finland, Norway and Sweden in 1995 and 2003

Laust H Mortensen  1 , Johan Rehnberg  2   3 , Espen Dahl  4 , Finn Diderichsen  1 , Jon Ivar Elstad  5 , Pekka Martikainen  6   2   7 , David Rehkopf  8 , Lasse Tarkiainen  6 , Johan Fritzell  3
Affiliations

Shape of the association between income and mortality: a cohort study of Denmark, Finland, Norway and Sweden in 1995 and 2003

Laust H Mortensen et al. BMJ Open. .

Abstract

Objectives: Prior work has examined the shape of the income-mortality association, but work has not compared gradients between countries. In this study, we focus on changes over time in the shape of income-mortality gradients for 4 Nordic countries during a period of rising income inequality. Context and time differentials in shape imply that the relationship between income and mortality is not fixed.

Setting: Population-based cohort study of Denmark, Finland, Norway and Sweden.

Participants: We collected data on individuals aged 25 or more in 1995 (n=12.98 million individuals, 0.84 million deaths) and 2003 (n=13.08 million individuals, 0.90 million deaths). We then examined the household size equivalised disposable income at the baseline year in relation to the rate of mortality in the following 5 years.

Results: A steep income gradient in mortality in men and women across all age groups except the oldest old in Denmark, Finland, Norway and Sweden. From the 1990s to 2000s mortality dropped, but generally more so in the upper part of the income distribution than in the lower part. As a consequence, the shape of the income gradient in mortality changed. The shift in the shape of the association was similar in all 4 countries.

Conclusions: A non-linear gradient exists between income and mortality in most cases and because of a more rapid mortality decline among those with high income the income gradient has become steeper over time.

Keywords: cohort study; health inequality; income; mortality.

PubMed Disclaimer

Conflict of interest statement

Conflicts of Interest: None declared.

Figures

Figure 1
Figure 1
Age-standardised mortality for individuals aged 25–64 at baseline. Full-drawn lines are 2003, dotted lines are 1995. The upper set of lines in each plot is for men, the lower set is for women.
Figure 2
Figure 2
Age-standardised mortality for individuals aged 65 or more at baseline. Full-drawn lines are 2003, dotted lines are 1995. The upper set of lines in each plot is for men, the lower set is for women.
Figure 3
Figure 3
Age-standardised mortality for individuals aged 25–64 at baseline plotted against the relative group median. Full-drawn lines are 2003, dotted lines are 1995. The upper set of lines in each plot is for men, the lower set is for women.
Figure 4
Figure 4
Association between age, income and mortality by age for men aged 25–64 at baseline. Full-drawn lines are 2003, dotted lines are 1995. There is a full-drawn and a dotted line for each 5-year age group, for example, the top two lines are for men aged 60–64 and the bottom two lines are men aged 25–29.
Figure 5
Figure 5
Association between age, income and mortality by age for women aged 25–64 at baseline. Full-drawn lines are 2003, dotted lines are 1995. There is a full-drawn and a dotted line for each 5-year age group, for example, the top two lines are for women aged 60–64 and the bottom two lines are women aged 25–29.
See this image and copyright information in PMC

References

    1. Mackenbach JP, Martikainen P, Looman CW et al. . The shape of the relationship between income and self-assessed health: an international study. Int J Epidemiol 2005;34:286–93. 10.1093/ije/dyh338 - DOI - PubMed
    1. Fritzell J, Nermo M, Lundberg O. The impact of income: assessing the relationship between income and health in Sweden. Scand J Public Health 2004;32:6–16. 10.1080/14034950310003971 - DOI - PubMed
    1. Rehkopf DH, Krieger N, Coull B et al. . Biologic risk markers for coronary heart disease: nonlinear associations with income. Epidemiology 2010;21:38–46. 10.1097/EDE.0b013e3181c30b89 - DOI - PubMed
    1. Rehkopf DH, Berkman LF, Coull B et al. . The non-linear risk of mortality by income level in a healthy population: US National Health and Nutrition Examination Survey mortality follow-up cohort, 1988–2001. BMC Public Health 2008;8:383 10.1186/1471-2458-8-383 - DOI - PMC - PubMed
    1. Marmot M. The influence of income on health: views of an epidemiologist. Health Aff (Millwood) 2002;21:31–46. 10.1377/hlthaff.21.2.31 - DOI - PubMed

Publication types