The Journals of Gerontology Series A: Biological Sciences and Medical Sciences Advance Access originally published online on June 17, 2009
The Journals of Gerontology Series A: Biological Sciences and Medical Sciences 2009 64A(10):1082-1089; doi:10.1093/gerona/glp078
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Social Inequality in Walking Speed in Early Old Age in the Whitehall II Study
Department of Epidemiology and Public Health, University College London
Address correspondence to Eric Brunner, MSc, PhD, FFPH, Department of Epidemiology and Public Health, University College London, 1-19 Torrington Place, London WC1E 6BT, UK. Email: e.brunner{at}ucl.ac.uk
| Abstract |
|---|
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.
Conclusion: Social inequality in walking speed is substantial in early old age and reflects many factors beyond the direct effects of physical health.
Keywords Socioeconomic position; Physical functioning; Epidemiology; Humans
Received: July 2, 2008; Accepted: March 15, 2009