title: Usual gait speed independently predicts mortality in very old people: a population-based study.
abstract: OBJECTIVE
  In older people, usual gait speed has been shown to independently predict mortality; however, less is known about whether usual gait speed is as informative in very old populations, in which prevalence of multimorbidity and disability is high. The aim of this study was to investigate if usual gait speed can independently predict all-cause mortality in very old people, and whether the prediction is influenced by dementia disorder, dependency in activities of daily living (ADL), or use of walking aids in the gait speed test.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Population-based study in northern Sweden and Finland (the Umeå 85+/GERDA Study).
  
  
  METHODS
  A total of 772 participants with a mean age of 89.6 years, 70% women, 33% with dementia disorders, 54% with ADL dependency, and 39% living in residential care facilities.
  
  
  METHODS
  Usual gait speed assessed over 2.4 meters and mortality followed-up for 5 years.
  
  
  RESULTS
  The mean ± SD gait speed was 0.52 ± 0.21 m/s for the 620 (80%) participants able to complete the gait speed test. Cox proportional hazard regression analyses adjusted for potential confounders were performed. Compared with the fastest gait speed group (≥ 0.64 m/s), the hazard ratio for mortality was for the following groups: unable = 2.27 (P < .001), ≤ 0.36 m/s = 1.97 (P = .001), 0.37 to 0.49 m/s = 1.99 (P < .001), 0.50 to 0.63 m/s = 1.11 (P = .604). No interaction effects were found between gait speed and age, sex, dementia disorder, dependency in ADLs, or use of walking aids.
  
  
  CONCLUSIONS
  Among people aged 85 or older, including people dependent in ADLs and with dementia disorders, usual gait speed was an independent predictor of 5-year all-cause mortality. Inability to complete the gait test or gait speeds slower than 0.5 m/s appears to be associated with higher mortality risk. Gait speed might be a useful clinical indicator of health status among very old people.
authors.affiliation: Department of Community Medicine and Rehabilitation, Physiotherapy, Umeå University, Umeå, Sweden. annika.toots@germed.umu.se
authors.forename: Annika
authors.initials: A
authors.lastname: Toots
authors.forename: Erik
authors.initials: E
authors.lastname: Rosendahl
authors.forename: Lillemor
authors.initials: L
authors.lastname: Lundin-Olsson
authors.forename: Peter
authors.initials: P
authors.lastname: Nordström
authors.forename: Yngve
authors.initials: Y
authors.lastname: Gustafson
authors.forename: Håkan
authors.initials: H
authors.lastname: Littbrand
mesh_terms: D000369:Aged, 80 and over; D003704:Dementia / Q000453:epidemiology; D004185:Disability Evaluation; D005260:Female; D005387:Finland; D005500:Follow-Up Studies; D005684:Gait; D006801:Humans; D008297:Male; D009026:Mortality; D016016:Proportional Hazards Models; D011446:Prospective Studies; D013548:Sweden