Mobility disability in the middle-aged: cross-sectional associations in the English Longitudinal Study of Ageing.

BACKGROUND Mobility (locomotor) disability is an early marker of disability progression, health care utilisation and institutionalisation in older people. Whether mobility disability has different causes in the middle-aged has received limited attention. OBJECTIVES To examine associations of mobility disability with sociodemographic, behaviour and disease status and to contrast these with associations in older groups. DESIGN Cross-sectional interview data from the 2002 English Longitudinal Study of Ageing. Mobility status based on reported difficulty walking a quarter of a mile (402 m). PARTICIPANTS A total of 11,392 community-living respondents aged 50 years and over. RESULTS In the middle-aged, 8% (95% CI 7-9%) of women and 9% (95% CI 8-11%) of men reported having much difficulty or being unable to walk a quarter of a mile, equating to 787,000 (95% CI 700,000-831,000) people in England. Factors which at least doubled odds of mobility disability in the middle-aged were chronic obstructive lung disease, angina, stroke, recently treated cancer, comorbidity, lower limb and back pain. Factors associated with mobility disability in older groups were similar. Thirty-eight per cent of mobility disability in the middle-aged population was related to high levels of lower limb pain and 15% to high levels of back pain. CONCLUSIONS Mobility disability in the middle-aged is relatively common. The associated conditions in the middle-aged are similar to those in older people. Lower limb and back pain make dominant population contributions to mobility disability. Prevention of later disability progression may require more attention being paid to mobility difficulties and its causes in the middle-aged.