title: Trajectories of Unhealthy Behaviors in Midlife and Risk of Disability at Older Ages in the Whitehall II Cohort Study.
abstract: Most of the evidence on the association between unhealthy behaviors and disability comes from studies in the elderly, where reverse causation and selection bias may distort associations; thus, studies based on midlife trajectories of health behaviors are needed. We examined the association of trajectories of four health behaviors (physical activity, fruit and vegetable consumption, smoking, alcohol), starting in midlife and over 20 years, with subsequent disability risk in early old age (range = 54-84 years) in the Whitehall II cohort study.
  
  
  
  Disability was assessed three times over 3 years. A hierarchical disability indicator was constructed; participants were considered disabled if they reported difficulties with mobility and instrumental activities of daily living or with mobility and instrumental and basic activities of daily living. Behavior trajectories were defined using group-based trajectory models. Multivariable generalized estimating equations logistic models were used to examine their independent associations with disability.
  
  
  
  Of 6,825 participants, 19.2% reported being disabled at least once. In mutually adjusted models, participants with persistent inactivity or declining physical activity, recent ex- or current smokers, and persistent/recent abstainers or persistent heavy drinkers had a higher disability risk, whereas fruit and vegetable consumption was not associated with disability. Disability risk increased progressively with the number of unhealthy behavior trajectories: the odds ratio of disability for 2-3 unhealthy trajectories was 2.69 (95% confidence interval = 2.26-3.19); these associations remained after adjustment for a wide range of covariates.
  
  
  
  Unhealthy behavior trajectories in midlife are associated with greater disability risk later in life.
authors.affiliation: INSERM, U1018, Centre for Research in Epidemiology and Population Health, Villejuif, France. fanny.artaud@inserm.fr.|University Versailles St-Quentin, UMRS-1018, Versailles, France.
authors.forename: Fanny
authors.initials: F
authors.lastname: Artaud
authors.affiliation: INSERM, U1018, Centre for Research in Epidemiology and Population Health, Villejuif, France.|Department of Epidemiology and Public Health, University College London, UK.|University Paris-Sud, UMRS-1018, Villejuif, France.
authors.forename: Séverine
authors.initials: S
authors.lastname: Sabia
authors.affiliation: INSERM, U1018, Centre for Research in Epidemiology and Population Health, Villejuif, France.|University Paris-Sud, UMRS-1018, Villejuif, France.
authors.forename: Aline
authors.initials: A
authors.lastname: Dugravot
authors.affiliation: Department of Epidemiology and Public Health, University College London, UK.
authors.forename: Mika
authors.initials: M
authors.lastname: Kivimaki
authors.affiliation: INSERM, U1018, Centre for Research in Epidemiology and Population Health, Villejuif, France.|Department of Epidemiology and Public Health, University College London, UK.|University Paris-Sud, UMRS-1018, Villejuif, France.
authors.forename: Archana
authors.initials: A
authors.lastname: Singh-Manoux
authors.affiliation: INSERM, U1018, Centre for Research in Epidemiology and Population Health, Villejuif, France.|University Paris-Sud, UMRS-1018, Villejuif, France.
authors.forename: Alexis
authors.initials: A
authors.lastname: Elbaz
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D004185:Disability Evaluation; D006233:Persons with Disabilities / Q000706:statistics & numerical data*; D005260:Female; D015577:Geriatric Assessment; D015438:Health Behavior; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D006113:United Kingdom / Q000453:epidemiology
keywords: Aging; Cohort study; Disability; Epidemiology; Health behaviors