Background: This study examined educational differences in decline in maximum gait speed over an 11-year follow-up in the general Finnish population aged 55 years and older and assessed the contribution of lifestyle factors, body mass index, physical workload, and chronic conditions on the association.
Method: Data from the nationally representative Health 2000 Survey and its 11-year follow-up were used. Participants aged 55 years and older with maximum gait speed measured at both time points were included (n = 1128). Information on education, age, sex, lifestyle factors, body mass index, physical workload, and chronic conditions was collected at baseline. General linear model was used to examine differences in decline in maximum gait speed between education groups. Mediation analyses using the product method was conducted to partition the total effect of education on decline in maximum gait speed into direct effect and indirect effect acting through mediators.
Results: Decline in maximum gait speed was greater in low and intermediate education groups in comparison to the high education group (0.24 m/s [95% confidence interval 0.21-0.26], 0.24 m/s [0.21-0.28], 0.10 m/s [0.07-0.14], respectively]. The most important mediators were higher body mass index and lifetime exposure to physical workload among the less educated, accounting for 10% and 11% of the total effect, respectively.
Conclusions: Education-based disparities in objectively measured mobility increase with age as lower education is associated with greater decline in gait speed. Higher body mass index and physical workload among less educated contributed most to the educational disparities in age-related decline in maximum gait speed.
Keywords: Health disparities; Mediation analyses; Physical function.
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