Social inequality in walking speed in early old age in the Whitehall II study.
BACKGROUND
We investigated social inequalities in walking speed in early old age.


METHODS
Walking speed was measured by timed 8-ft (2.44 m) test in 6,345 individuals, with mean age of 61.1 (SD 6.0) years. Current or last known civil service employment grade defined socioeconomic position.


RESULTS
Mean walking speed was 1.36 (SD 0.29) m/s in men and 1.21 (SD 0.30) in women. Average age- and ethnicity-adjusted walking speed was approximately 13% higher in the highest employment grade compared with the lowest. Based on the relative index of inequality (RII), the difference in walking speed across the social hierarchy was 0.15 m/s (95% confidence interval [CI] 0.12-0.18) in men and 0.17 m/s (0.12-0.22) in women, corresponding to an age-related difference of 18.7 (13.6-23.8) years in men and 14.9 (9.9-19.9) years in women. The RII for slow walking speed (logistic model for lowest sex-specific quartile vs others) adjusted for age, sex, and ethnicity was 3.40 (2.64-4.36). Explanatory factors for the social gradient in walking speed included Short-Form 36 physical functioning, labor market status, financial insecurity, height, and body mass index. Demographic, psychosocial, behavioral, biologic, and health factors in combination accounted for 40% of social inequality in walking speed.


CONCLUSIONS
Social inequality in walking speed is substantial in early old age and reflects many factors beyond the direct effects of physical health.
Brunner
Eric
E
Department of Epidemiology and Public Health, University College London, UK. e.brunner@ucl.ac.uk
Shipley
Martin
M
Spencer
Victoria
V
Kivimaki
Mika
M
Chandola
Tarani
T
Gimeno
David
D
Singh-Manoux
Archana
A
Guralnik
Jack
J
Marmot
Michael
M
D000367:Age Factors; D000368:Aged; D015992:Body Mass Index; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004651:Employment; D005260:Female; D005684:Gait; D015438:Health Behavior; D006304:Health Status; D006801:Humans; D008131:London; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D012923:Social Class