Socio-economic disadvantage from childhood to adulthood and locomotor function in old age: a lifecourse analysis of the Boyd Orr and Caerphilly prospective studies

Background Socio-economic influences over a lifetime impact on health and may contribute to poor physical functioning in old age. Methods The authors examined the impact of both childhood and adulthood socio-economic factors on locomotor function at 63-86 years (measured with the get up and go timed walk and flamingo balance test) in the UK-based Boyd Orr (n = 405) and Caerphilly (n 1196) prospective cohorts. Results There was a marked reduction in walking speed and balance time with increasing age. Each year of age was associated with a 1.7% slower walk time and a 14% increased odds of poor balance. Participants who moved from a low socio-economic position in childhood to a high socio-economic position in adulthood had 3% slower walking times (95% CI -2% to 8%) than people with a high socio-economic position in both periods. Participants who moved from a high socio-economic position in childhood to a low adulthood socio-economic position had 5% slower walking times (95% CI -2% to 12%). Participants with a low socio-economic position in both periods had 10% slower walking times (95% CI 5% to 16%; p for trend<0.001). In Boyd Orr, low socio-economic position in childhood was associated with poor balance in old age (OR per worsening category = 1.26; 95% CI 1.01 to 1.57; p = 0.043), as was socio-economic position in adulthood (OR = 1.71; 95% CI 1.20 to 2.45; p = 0.003). Similar associations were not observed in Caerphilly. Conclusion Accumulating socio-economic disadvantage from childhood to adulthood is associated with slower walking time in old age, with mixed results for balance ability.