PT  - JOURNAL ARTICLE
AU  - Denes Stefler
AU  - Matthew Prina
AU  - Yu-Tzu Wu
AU  - Albert Sánchez-Niubò
AU  - Wentian Lu
AU  - Josep Maria Haro
AU  - Michael Marmot
AU  - Martin Bobak
TI  - Socioeconomic inequalities in physical and cognitive functioning: cross-sectional evidence from 37 cohorts across 28 countries in the ATHLOS project
AID  - 10.1136/jech-2020-214714
DP  - 2021 Feb 28
TA  - Journal of Epidemiology and Community Health
PG  - jech-2020-214714
4099  - http://jech.bmj.com/content/early/2021/02/28/jech-2020-214714.short
4100  - http://jech.bmj.com/content/early/2021/02/28/jech-2020-214714.full
AB  - Background Physical and cognitive functioning in older age follows a socioeconomic gradient but it is unclear whether the strength of the association differs between populations. Using harmonised data from an international collaboration of cohort studies, we assessed socioeconomic inequalities in physical and cognitive functioning and explored if the extent of inequalities varied across countries based on their economic strength or wealth distribution.Methods Harmonised data from 37 population-based cohorts in 28 countries were used, with an overall sample size of 126 765. Socioeconomic position of participants was indicated by education and household income. Physical functioning was assessed by self-reported mobility and activities of daily living; and cognitive functioning by memory and verbal fluency tests. Relative (RII) and slope (SII) index of inequality were calculated in each cohort, and their association with the source country’s Gross Domestic Product (GDP) and Gini-index was assessed with correlation and cross-level interaction in multilevel models.Results RII and SII values indicated consistently higher risk of low physical and cognitive functioning in participants with lower education or income across cohorts. Regarding RII, there were weak but statistically significant correlations and interactions with GDP and Gini-index, suggesting larger inequalities in countries with lower Gini-index and higher GDP. For SII, no such correlations were observed.Conclusion This study confirms that socioeconomic inequalities in physical and cognitive functioning exist across different social contexts but the magnitude of these inequalities varies. Relative inequalities appear to be larger in higher-income countries but it remains to be seen whether such observation can be replicated.