Social integration and mortality across the life course: findings from the Tromsø study
File(s)
Published version
Author(s)
Ugarteche Pérez, Ainhoa
El Rashidi, Nadine
Farbu, Erlend Hoftun
Castagné, Raphaële
Grimsgaard, Sameline
Type
Journal Article
Abstract
Context
Poor social relationships have been associated with increased mortality risk. Configurations of social relationships vary across the life course, affecting the association with mortality. We investigated the relationship between social integration and mortality in four age groups and to examine three blocks of potential intermediate variables.
Methods
Tromsø Study wave 4 and 6 data and mortality events in the Norwegian Population Registry were linked. A three-level (low, medium, high) social integration index (SII) was constructed from scores to three related items: social participation, living with spouse and frequency of contact with friends. Adjusted cox-regression models and including intermediate variables in blocks (1:behavioral, 2:psychosocial resources, 3:biological markers) were conducted in the study population (N = 9879) and in age-stratified subsamples: [25–52]y. (N = 6785); [53–59]y. (N = 1679); [60–65]y. (N = 846); [66–74]y. (N = 569). Additional sex-stratified and causes-of-death models (cancer, cardiovascular diseases, neuropsychiatric conditions and other deaths) were constructed.
Results
A graded SII and mortality risk association was observed in confounder-adjusted models in the total study population: individuals with medium and low SII had incrementally higher risk of mortality compared to those with high SII (HRmediumSII[95%CI] = 1.15 [1.02; 1.31], HRlowSII[95%CI] = 1.42[1.14; 1.76]). This association was mainly observed in the [53–59]y. group and among men. Health behaviors and the psychosocial resources block partly attenuated the association, but biological markers did not. Low SII was particularly associated with deaths from “other causes”, including respiratory conditions, and to a lesser extent with deaths from cardiovascular disease and cancer.
Conclusion
Our study consolidates evidence on the relationship between social integration and mortality risk, especially in mid-adulthood, and suggests some potential underlying pathways. To reduce mortality risk inequalities, we encourage structurally addressing social marginalization.
Poor social relationships have been associated with increased mortality risk. Configurations of social relationships vary across the life course, affecting the association with mortality. We investigated the relationship between social integration and mortality in four age groups and to examine three blocks of potential intermediate variables.
Methods
Tromsø Study wave 4 and 6 data and mortality events in the Norwegian Population Registry were linked. A three-level (low, medium, high) social integration index (SII) was constructed from scores to three related items: social participation, living with spouse and frequency of contact with friends. Adjusted cox-regression models and including intermediate variables in blocks (1:behavioral, 2:psychosocial resources, 3:biological markers) were conducted in the study population (N = 9879) and in age-stratified subsamples: [25–52]y. (N = 6785); [53–59]y. (N = 1679); [60–65]y. (N = 846); [66–74]y. (N = 569). Additional sex-stratified and causes-of-death models (cancer, cardiovascular diseases, neuropsychiatric conditions and other deaths) were constructed.
Results
A graded SII and mortality risk association was observed in confounder-adjusted models in the total study population: individuals with medium and low SII had incrementally higher risk of mortality compared to those with high SII (HRmediumSII[95%CI] = 1.15 [1.02; 1.31], HRlowSII[95%CI] = 1.42[1.14; 1.76]). This association was mainly observed in the [53–59]y. group and among men. Health behaviors and the psychosocial resources block partly attenuated the association, but biological markers did not. Low SII was particularly associated with deaths from “other causes”, including respiratory conditions, and to a lesser extent with deaths from cardiovascular disease and cancer.
Conclusion
Our study consolidates evidence on the relationship between social integration and mortality risk, especially in mid-adulthood, and suggests some potential underlying pathways. To reduce mortality risk inequalities, we encourage structurally addressing social marginalization.
Date Issued
2025-11-28
Date Acceptance
2025-10-25
Citation
BMC Public Health, 2025, 25
ISSN
1471-2458
Publisher
BMC
Journal / Book Title
BMC Public Health
Volume
25
Issue
1
Copyright Statement
© The Author(s) 2025. Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.
Publication Status
Published
Article Number
4186
Date Publish Online
2025-11-28