Level of Education Modifies Asthma Mortality in Norway and Sweden. The Nordic EpiLung Study

Helena Backman; Laxmi Bhatta; Linnea Hedman; Ben Brumpton; Iida Vähätalo; Paul G Lassmann-Klee; Bright I Nwaru; Linda Ekerljung; Steinar Krokstad; Sigrid Anna Aalberg Vikjord; Anne Lindberg; Hannu Kankaanranta; Eva Rönmark; Arnulf Langhammer

doi:10.2147/JAA.S450103

Level of Education Modifies Asthma Mortality in Norway and Sweden. The Nordic EpiLung Study

J Asthma Allergy. 2024 Mar 18:17:209-218. doi: 10.2147/JAA.S450103. eCollection 2024.

Authors

Helena Backman^#¹, Laxmi Bhatta^#^{2

3}, Linnea Hedman¹, Ben Brumpton², Iida Vähätalo^{4

5}, Paul G Lassmann-Klee⁶, Bright I Nwaru⁷, Linda Ekerljung⁷, Steinar Krokstad^{8

9}, Sigrid Anna Aalberg Vikjord², Anne Lindberg¹⁰, Hannu Kankaanranta⁷, Eva Rönmark^#¹, Arnulf Langhammer^#⁸

Affiliations

¹ Section of Sustainable Health/ the OLIN Unit, Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.
² K.G. Jebsen Center for Genetic Epidemiology, Department of Public Health and Nursing, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology NTNU, Trondheim, Norway.
³ Division of Mental Health Care, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.
⁴ Department of Respiratory Medicine, Seinäjoki Central Hospital, Seinäjoki, Finland.
⁵ Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.
⁶ Clinical Physiology and Nuclear Medicine Unit, Helsinki University Hospital's Diagnostic Center and University of Helsinki, Helsinki, Finland.
⁷ Krefting Research Centre, Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
⁸ HUNT Research Centre, Department of Public Health and Nursing, NTNU, Norwegian University of Science and Technology, Levanger, Norway.
⁹ Nord-Trøndelag Hospital Trust, Levanger Hospital, Levanger, Norway.
¹⁰ Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.

^# Contributed equally.

Abstract

Background and aim: The relationship between socioeconomic status (SES), asthma and mortality is complex and multifaceted, and it is not established if educational level modifies the association between asthma and mortality. The aim was to study the association between asthma and mortality in Sweden and Norway and to what extent educational level modifies this association.

Participants and methods: Within the Nordic EpiLung Study, >56,000 individuals aged 30-69 years participated in population-based surveys on asthma and associated risk factors in Sweden and Norway during 2005-2007. Data on educational level and 10-year all-cause mortality were linked by national authorities. The fraction of mortality risk attributable to asthma was calculated, and Cox regression was used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI) for mortality related to asthma, stratified by educational level.

Results: In total, 5.5% of all deaths was attributed to asthma. When adjusted for potential confounders, the HR for mortality related to asthma was 1.71 (95% CI 1.52-1.93). Those with primary level of education had higher hazard of all-cause death related to asthma than those with tertiary level (HR 1.80, 95% CI 1.48-2.18, vs HR 1.39, 95% CI 0.99-1.95).

Conclusion: Asthma was associated with an overall 71% increased all-cause mortality and 5.5% of deaths can be attributed to asthma. Educational levels modified the risk of mortality associated with asthma, with the highest risk among those with primary education.

Keywords: cohort; epidemiology; prognosis.

Grants and funding

Financial support was provided by the Nordic Council, the Swedish Research Council for Health, Working Life and Welfare (FORTE, Dnr 2022-00381), the Swedish Research Council, the Swedish Heart-Lung foundation, Northern County Councils’ Regional Federation, a regional agreement between Umeå University and Västerbotten County Council (ALF), Region Norrbotten, the VBG Group Herman Krefting Foundation for Asthma and Allergy Research, Sweden, the Swedish Asthma and Allergy Foundation, and ALF agreement (Grants from the Swedish state under the agreement between the Swedish Government and the county councils). LB and BB received support from the K.G. Jebsen Center for Genetic Epidemiology funded by Stiftelsen Kristian Gerhard Jebsen; Faculty of Medicine and Health Sciences, NTNU; The Liaison Committee for education, research and innovation in Central Norway; and the Joint Research Committee between St Olavs Hospital and the Faculty of Medicine and Health Sciences, NTNU.