Cargando…

Social class and the risk of dementia: A systematic review and meta-analysis of the prospective longitudinal studies

BACKGROUND: The association between belonging to a disadvantaged socio-economic status or social class and health outcomes has been consistently documented during recent decades. However, a meta-analysis quantifying the association between belonging to a lower social class and the risk of dementia h...

Descripción completa

Detalles Bibliográficos
Autores principales: Bodryzlova, Yuliya, Kim, Alexie, Michaud, Xavier, André, Claire, Bélanger, Emmanuelle, Moullec, Grégory
Formato: Online Artículo Texto
Lenguaje:English
Publicado: SAGE Publications 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10642219/
https://www.ncbi.nlm.nih.gov/pubmed/35815546
http://dx.doi.org/10.1177/14034948221110019
_version_ 1785146920218394624
author Bodryzlova, Yuliya
Kim, Alexie
Michaud, Xavier
André, Claire
Bélanger, Emmanuelle
Moullec, Grégory
author_facet Bodryzlova, Yuliya
Kim, Alexie
Michaud, Xavier
André, Claire
Bélanger, Emmanuelle
Moullec, Grégory
author_sort Bodryzlova, Yuliya
collection PubMed
description BACKGROUND: The association between belonging to a disadvantaged socio-economic status or social class and health outcomes has been consistently documented during recent decades. However, a meta-analysis quantifying the association between belonging to a lower social class and the risk of dementia has yet to be performed. In the present work, we sought to summarise the results of prospective, longitudinal studies on this topic. METHODS: We conducted a systematic review and meta-analysis of prospective, longitudinal studies measuring the association between indicators of social class and the risk of all-cause/Alzheimer’s dementia. The search was conducted in four databases (Medline, Embase, Web of Science and PsychInfo). Inclusion criteria for this systematic review and meta-analysis were: (a) longitudinal prospective study, (b) aged ⩾60 years at baseline, (c) issued from the general population, (d) no dementia at baseline and (e) mention of social class as exposure. Exclusion criteria were: (a) study of rare dementia types (e.g. frontotemporal dementia), (b) abstract-only papers and (c) articles without full text available. The Newcastle–Ottawa scale was used to assess the risk of bias in individual studies. We calculated the overall pooled relative risk of dementia for different social class indicators, both crude and adjusted for sex, age and the year of the cohort start. RESULTS: Out of 4548 screened abstracts, 15 were included in the final analysis (76,561 participants, mean follow-up 6.7 years (2.4–25 years), mean age at baseline 75.1 years (70.6–82.1 years), mean percentage of women 58%). Social class was operationalised as levels of education, occupational class, income level, neighbourhood disadvantage and wealth. Education (relative risk (RR)=2.48; confidence interval (CI) 1.71–3.59) and occupational class (RR=2.09; CI 1.18–3.69) but not income (RR=1.28; CI 0.81–2.04) were significantly associated with the risk of dementia in the adjusted model. Some of the limitations of this study are the inclusion of studies predominantly conducted in high-income countries and the exclusion of social mobility in our analysis. CONCLUSIONS: We conclude that there is a significant association between belonging to a social class and the risk of dementia, with education and occupation being the most relevant indicators of social class regarding this risk. Studying the relationship between belonging to a disadvantaged social class and dementia risk might be a fruitful path to diminishing the incidence of dementia over time. However, a narrow operationalisation of social class that only includes education, occupation and income may reduce the potential for such studies to inform social policies.
format Online
Article
Text
id pubmed-10642219
institution National Center for Biotechnology Information
language English
publishDate 2022
publisher SAGE Publications
record_format MEDLINE/PubMed
spelling pubmed-106422192023-11-14 Social class and the risk of dementia: A systematic review and meta-analysis of the prospective longitudinal studies Bodryzlova, Yuliya Kim, Alexie Michaud, Xavier André, Claire Bélanger, Emmanuelle Moullec, Grégory Scand J Public Health Literature Reviews BACKGROUND: The association between belonging to a disadvantaged socio-economic status or social class and health outcomes has been consistently documented during recent decades. However, a meta-analysis quantifying the association between belonging to a lower social class and the risk of dementia has yet to be performed. In the present work, we sought to summarise the results of prospective, longitudinal studies on this topic. METHODS: We conducted a systematic review and meta-analysis of prospective, longitudinal studies measuring the association between indicators of social class and the risk of all-cause/Alzheimer’s dementia. The search was conducted in four databases (Medline, Embase, Web of Science and PsychInfo). Inclusion criteria for this systematic review and meta-analysis were: (a) longitudinal prospective study, (b) aged ⩾60 years at baseline, (c) issued from the general population, (d) no dementia at baseline and (e) mention of social class as exposure. Exclusion criteria were: (a) study of rare dementia types (e.g. frontotemporal dementia), (b) abstract-only papers and (c) articles without full text available. The Newcastle–Ottawa scale was used to assess the risk of bias in individual studies. We calculated the overall pooled relative risk of dementia for different social class indicators, both crude and adjusted for sex, age and the year of the cohort start. RESULTS: Out of 4548 screened abstracts, 15 were included in the final analysis (76,561 participants, mean follow-up 6.7 years (2.4–25 years), mean age at baseline 75.1 years (70.6–82.1 years), mean percentage of women 58%). Social class was operationalised as levels of education, occupational class, income level, neighbourhood disadvantage and wealth. Education (relative risk (RR)=2.48; confidence interval (CI) 1.71–3.59) and occupational class (RR=2.09; CI 1.18–3.69) but not income (RR=1.28; CI 0.81–2.04) were significantly associated with the risk of dementia in the adjusted model. Some of the limitations of this study are the inclusion of studies predominantly conducted in high-income countries and the exclusion of social mobility in our analysis. CONCLUSIONS: We conclude that there is a significant association between belonging to a social class and the risk of dementia, with education and occupation being the most relevant indicators of social class regarding this risk. Studying the relationship between belonging to a disadvantaged social class and dementia risk might be a fruitful path to diminishing the incidence of dementia over time. However, a narrow operationalisation of social class that only includes education, occupation and income may reduce the potential for such studies to inform social policies. SAGE Publications 2022-07-10 2023-12 /pmc/articles/PMC10642219/ /pubmed/35815546 http://dx.doi.org/10.1177/14034948221110019 Text en © Author(s) 2022 https://creativecommons.org/licenses/by-nc/4.0/This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License (https://creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access pages (https://us.sagepub.com/en-us/nam/open-access-at-sage).
spellingShingle Literature Reviews
Bodryzlova, Yuliya
Kim, Alexie
Michaud, Xavier
André, Claire
Bélanger, Emmanuelle
Moullec, Grégory
Social class and the risk of dementia: A systematic review and meta-analysis of the prospective longitudinal studies
title Social class and the risk of dementia: A systematic review and meta-analysis of the prospective longitudinal studies
title_full Social class and the risk of dementia: A systematic review and meta-analysis of the prospective longitudinal studies
title_fullStr Social class and the risk of dementia: A systematic review and meta-analysis of the prospective longitudinal studies
title_full_unstemmed Social class and the risk of dementia: A systematic review and meta-analysis of the prospective longitudinal studies
title_short Social class and the risk of dementia: A systematic review and meta-analysis of the prospective longitudinal studies
title_sort social class and the risk of dementia: a systematic review and meta-analysis of the prospective longitudinal studies
topic Literature Reviews
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10642219/
https://www.ncbi.nlm.nih.gov/pubmed/35815546
http://dx.doi.org/10.1177/14034948221110019
work_keys_str_mv AT bodryzlovayuliya socialclassandtheriskofdementiaasystematicreviewandmetaanalysisoftheprospectivelongitudinalstudies
AT kimalexie socialclassandtheriskofdementiaasystematicreviewandmetaanalysisoftheprospectivelongitudinalstudies
AT michaudxavier socialclassandtheriskofdementiaasystematicreviewandmetaanalysisoftheprospectivelongitudinalstudies
AT andreclaire socialclassandtheriskofdementiaasystematicreviewandmetaanalysisoftheprospectivelongitudinalstudies
AT belangeremmanuelle socialclassandtheriskofdementiaasystematicreviewandmetaanalysisoftheprospectivelongitudinalstudies
AT moullecgregory socialclassandtheriskofdementiaasystematicreviewandmetaanalysisoftheprospectivelongitudinalstudies