Does prolonged education causally affect dementia risk when adult socioeconomic status is not altered? A Swedish natural experiment in 1.3 million individuals
(2021) In American Journal of Epidemiology 190(5). p.817-826- Abstract
Intervening on modifiable risk factors to prevent dementia is of key importance, since progress-modifying treatments are not currently available. Education is inversely associated with dementia risk, but causality and mechanistic pathways remain unclear. We aimed to examine the causality of this relationship in Sweden using, as a natural experiment, data on a compulsory schooling reform that extended primary education by 1 year for 70% of the population between 1936 and 1949. The reform introduced substantial exogenous variation in education that was unrelated to pupils' characteristics. We followed 18 birth cohorts (n = 1,341,842) from 1985 to 2016 (up to ages 79-96 years) for a dementia diagnosis in the National Inpatient and Cause of... (More)
Intervening on modifiable risk factors to prevent dementia is of key importance, since progress-modifying treatments are not currently available. Education is inversely associated with dementia risk, but causality and mechanistic pathways remain unclear. We aimed to examine the causality of this relationship in Sweden using, as a natural experiment, data on a compulsory schooling reform that extended primary education by 1 year for 70% of the population between 1936 and 1949. The reform introduced substantial exogenous variation in education that was unrelated to pupils' characteristics. We followed 18 birth cohorts (n = 1,341,842) from 1985 to 2016 (up to ages 79-96 years) for a dementia diagnosis in the National Inpatient and Cause of Death registers and fitted Cox survival models with stratified baseline hazards at the school-district level, chronological age as the time scale, and cohort indicators. Analyses indicated very small or negligible causal effects of education on dementia risk (main hazard ratio = 1.01, 95% confidence interval: 0.98, 1.04). Multiple sensitivity checks considering only compliers, the pre-/post-design, differences in health-care-seeking behavior, and the impact of exposure misclassification left the results essentially unaltered. The reform had limited effects on further adult socioeconomic outcomes, such as income. Our findings suggest that without mediation through adult socioeconomic position, education cannot be uncritically considered a modifiable risk factor for dementia.
(Less)
- author
- Seblova, Dominika ; Fischer, Martin LU ; Fors, Stefan ; Johnell, Kristina ; Karlsson, Martin LU ; Nilsson, Therese LU ; Svensson, Anna C. ; Lovden, Martin LU and Lager, Anton
- organization
- publishing date
- 2021
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Alzheimer disease, Causal estimation, Compulsory schooling, Dementia, Education reform, Natural experiments
- in
- American Journal of Epidemiology
- volume
- 190
- issue
- 5
- pages
- 10 pages
- publisher
- Oxford University Press
- external identifiers
-
- scopus:85105657404
- pmid:33226079
- ISSN
- 0002-9262
- DOI
- 10.1093/aje/kwaa255
- language
- English
- LU publication?
- yes
- id
- f05c5bf7-9111-4aa0-8577-d2480e8a19d2
- date added to LUP
- 2020-09-23 10:41:41
- date last changed
- 2024-06-12 20:42:14
@article{f05c5bf7-9111-4aa0-8577-d2480e8a19d2,
abstract = {{<p>Intervening on modifiable risk factors to prevent dementia is of key importance, since progress-modifying treatments are not currently available. Education is inversely associated with dementia risk, but causality and mechanistic pathways remain unclear. We aimed to examine the causality of this relationship in Sweden using, as a natural experiment, data on a compulsory schooling reform that extended primary education by 1 year for 70% of the population between 1936 and 1949. The reform introduced substantial exogenous variation in education that was unrelated to pupils' characteristics. We followed 18 birth cohorts (n = 1,341,842) from 1985 to 2016 (up to ages 79-96 years) for a dementia diagnosis in the National Inpatient and Cause of Death registers and fitted Cox survival models with stratified baseline hazards at the school-district level, chronological age as the time scale, and cohort indicators. Analyses indicated very small or negligible causal effects of education on dementia risk (main hazard ratio = 1.01, 95% confidence interval: 0.98, 1.04). Multiple sensitivity checks considering only compliers, the pre-/post-design, differences in health-care-seeking behavior, and the impact of exposure misclassification left the results essentially unaltered. The reform had limited effects on further adult socioeconomic outcomes, such as income. Our findings suggest that without mediation through adult socioeconomic position, education cannot be uncritically considered a modifiable risk factor for dementia. </p>}},
author = {{Seblova, Dominika and Fischer, Martin and Fors, Stefan and Johnell, Kristina and Karlsson, Martin and Nilsson, Therese and Svensson, Anna C. and Lovden, Martin and Lager, Anton}},
issn = {{0002-9262}},
keywords = {{Alzheimer disease; Causal estimation; Compulsory schooling; Dementia; Education reform; Natural experiments}},
language = {{eng}},
number = {{5}},
pages = {{817--826}},
publisher = {{Oxford University Press}},
series = {{American Journal of Epidemiology}},
title = {{Does prolonged education causally affect dementia risk when adult socioeconomic status is not altered? A Swedish natural experiment in 1.3 million individuals}},
url = {{http://dx.doi.org/10.1093/aje/kwaa255}},
doi = {{10.1093/aje/kwaa255}},
volume = {{190}},
year = {{2021}},
}