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Public Transportation Use and Cognitive Function in Older Age: A Quasiexperimental Evaluation of the Free Bus Pass Policy in the United Kingdom

Research output: Contribution to journalArticle

Original languageEnglish
Pages (from-to)1774-1783
Number of pages10
JournalAmerican Journal of Epidemiology
Volume188
Issue number10
Early online date28 Jun 2019
DOIs
Publication statusPublished - 1 Oct 2019

King's Authors

Abstract

This quasi-experimental study examines whether the introduction of an age-friendly transportation policy, free bus passes for older adults, increased public transport use and in turn impacted cognitive function among older people in England. Data comes from 7 waves (2002-2014) of the English Longitudinal Study of Ageing (n =17,953), which measures global cognitive function, memory, executive function, and processing speed before and after the bus pass was introduced in 2006. The analytical strategy is an instrumental variable approach with fixed effects, which exploits the age-eligibility criteria for free bus passes and addresses bias due to reverse causality, measurement error, and time-invariant confounding. Eligibility for the bus pass is associated with a 7% increase in public transport use. The increase in public transportation use is associated with a 0.346 (95% confidence interval (CI): 0.017,0.674) increase in the global cognitive function Z score and with a 0.546 (95% CI: 0.111,0.982) increase in memory Z score. Free bus passes increase public transport use, which in turn benefits cognitive function in older age. Public transport use may promote cognitive health through encouraging intellectually, socially, and physically active lifestyles. Transport policies may serve as public health tools to promote cognitive health in ageing populations.

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