title: Gait Speed and Processing Speed as Clinical Markers for Geriatric Health Outcomes.
abstract: OBJECTIVE
  This study investigates the independent and combined potential of slowed gait speed and slowed processing speed as predictors of adverse health outcomes. The role of depressive symptoms in these associations is also investigated.
  
  
  METHODS
  In the prospective cohort study, using the Longitudinal Aging Study Amsterdam database, three study samples for each outcome variable were defined: persistent cognitive decline (PCD; N = 1,271, 13 years of follow-up), falls (N = 1,282, 6 years of follow-up), and mortality (N = 1,559, age 74.9 ± 5.8, 21 years of follow-up). At baseline, gait speed (6-m walk with a turn at 3 m), processing speed (coding task), depressive symptoms (Center for Epidemiologic Studies Depression Scale), and basic demographic data were assessed. Also, time to PCD, falls, and mortality were assessed. Cox (for PCD and mortality) and stratified Cox (for falls) regression models were used.
  
  
  RESULTS
  Slowed processing speed predicted PCD (HR: 7.8; 95% CI: 3.3-18.8), slowed gait speed predicted falls (HR: 1.3; 95% CI: 1.0-1.5), and both measures predicted mortality (gait speed HR: 2.1; 95% CI: 1.6-2.6; processing speed HR: 1.9; 95% CI: 1.6-2.4). Each association remained significant after adjusting for the other slowing symptom. Slowed processing speed only predicted falls in the presence of slowed gait (interaction). A slowing sum score that combines both slowing symptoms predicted all three outcomes. The associations were not influenced by depressive symptoms.
  
  
  CONCLUSIONS
  Slowing of thought is as relevant as slowing of movement to predict adverse health outcomes, because they seem to represent separate underlying pathologies.
authors.affiliation: Department of Old Age Psychiatry, Altrecht Institute for Mental Health Care Utrecht, Utrecht, The Netherlands; EMGO Institute for Health and Care Research, VU University Medical Center Amsterdam, Amsterdam, The Netherlands. Electronic address: j.sanders@vumc.nl.
authors.forename: Joost B
authors.initials: JB
authors.lastname: Sanders
authors.affiliation: EMGO Institute for Health and Care Research, VU University Medical Center Amsterdam, Amsterdam, The Netherlands; Department of Psychiatry, VU University Medical Center Amsterdam, Amsterdam, The Netherlands.
authors.forename: Marijke A
authors.initials: MA
authors.lastname: Bremmer
authors.affiliation: Department of Psychiatry, VU University Medical Center Amsterdam, Amsterdam, The Netherlands; GGZInGeest, Amsterdam, The Netherlands.
authors.forename: Hannie C
authors.initials: HC
authors.lastname: Comijs
authors.affiliation: Department of Epidemiology and Biostatistics, VU University Medical Center Amsterdam, Amsterdam, The Netherlands.
authors.forename: Peter M
authors.initials: PM
authors.lastname: van de Ven
authors.affiliation: EMGO Institute for Health and Care Research, VU University Medical Center Amsterdam, Amsterdam, The Netherlands; Department of Epidemiology and Biostatistics, VU University Medical Center Amsterdam, Amsterdam, The Netherlands.
authors.forename: Dorly J H
authors.initials: DJH
authors.lastname: Deeg
authors.affiliation: EMGO Institute for Health and Care Research, VU University Medical Center Amsterdam, Amsterdam, The Netherlands; Department of Psychiatry, VU University Medical Center Amsterdam, Amsterdam, The Netherlands; GGZInGeest, Amsterdam, The Netherlands.
authors.forename: Aartjan T F
authors.initials: ATF
authors.lastname: Beekman
mesh_terms: D000058:Accidental Falls / Q000706:statistics & numerical data*; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D060825:Cognitive Dysfunction / Q000453:epidemiology*; D003863:Depression / Q000453:epidemiology*; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009026:Mortality; D009426:Netherlands / Q000453:epidemiology; D011597:Psychomotor Performance / Q000502:physiology*; D013997:Time Factors; D000072797:Walking Speed / Q000502:physiology*
keywords: Gait speed; adverse health outcomes; depressive symptoms; processing speed