Open Access Research article

Explanations of socioeconomic differences in changes in physical function in older adults: results from the Longitudinal Aging Study Amsterdam

Annemarie Koster1*, Hans Bosma1, Marjolein I Broese van Groenou2, Gertrudis IJM Kempen1, Brenda WJH Penninx34, Jacques ThM van Eijk1 and Dorly JH Deeg4

Author Affiliations

1 Department of Health Care Studies, Section Medical Sociology, Universiteit Maastricht, PO Box 616, 6200 MD Maastricht, The Netherlands

2 Department of Social-Cultural Sciences, Faculty of Social Sciences, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands

3 Department of Psychiatry, VU University Medical Center, Valeriusplein 91075 BG Amsterdam, The Netherlands

4 Institute for Research in Extramural Medicine, LASA, VU University Medical Center, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands

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BMC Public Health 2006, 6:244  doi:10.1186/1471-2458-6-244

Published: 5 October 2006

Abstract

Background

This study examines the association between socioeconomic status and changes in physical function in younger- (aged 55–70 years) and older-old (aged 70–85 years) adults and seeks to determine the relative contribution of diseases, behavioral, and psychosocial factors in explaining this association.

Methods

Data were from 2,366 men and women, aged 55–85 years, participating in the Longitudinal Aging Study Amsterdam (LASA). Two indicators of socioeconomic status were used: education and income. Physical function was measured by self-reported physical ability over nine years of follow-up.

Results

In older adults, low socioeconomic status was related to a poorer level of physical function during nine years of follow-up. In subjects who were between 55 and 70 years old, there was an additional significant socioeconomic-differential decline in physical function, while socioeconomic differentials did not further widen in subjects 70 years and older. Behavioral factors, mainly BMI and physical activity, largely explained the socioeconomic differences in physical function in the youngest age group, while psychosocial factors reduced socioeconomic status differences most in the oldest age group.

Conclusion

The findings indicate age-specificity of both the pattern of socioeconomic status differences in function in older persons and the mechanisms underlying these associations.