title: Instrumental and Non-Instrumental Evaluation of 4-Meter Walking Speed in Older Individuals.
abstract: BACKGROUND
  Manual measurement of 4-meter gait speed by a stopwatch is the gold standard test for functional assessment in older adults. However, the accuracy of this technique may be biased by several factors, including intra- and inter-operator variability. Instrumental techniques of measurement using accelerometers may have a higher accuracy. Studies addressing the concordance between these two techniques are missing. The aim of the present community-based observational study was to compare manual and instrumental measurements of 4-meter gait speed in older individuals and to assess their relationship with other indicators of physical performance.
  
  
  METHODS
  One-hundred seventy-two (69 men, 103 women) non-disabled community-dwellers aged ≥65 years were enrolled. They underwent a comprehensive geriatric assessment including physical function by Short Physical Performance Battery (SPPB), hand grip strength, and 6-minute walking test (6MWT). Timed usual walking speed on a 4-meter course was assessed by using both a stopwatch (4-meter manual measurement, 4-MM) and a tri-axial accelerometer (4-meter automatic measurement, 4-MA). Correlations between these performance measures were evaluated separately in men and women by partial correlation coefficients.
  
  
  RESULTS
  In both genders, 4-MA was associated with 4-MM (men r = 0.62, p<0.001; women r = 0.73, p<0.001), handgrip strength (men r = 0.40, p = 0.005; women r = 0.29, p = 0.001) and 6MWT (men r = 0.50, p = 0.0004; women r = 0.22, p = 0.048). 4-MM was associated with handgrip strength and 6MWT in both men and women. Considering gait speed <0.6 m/s as diagnostic of dismobility syndrome, the two methods of assessment disagreed, with a different categorization of subjects, in 19% of men and 23% of women. The use of accelerometer resulted in 29 (13 M, 16 F) additional diagnoses of dismobility, compared with the 4-MM.
  
  
  CONCLUSIONS
  In an older population, the concordance of gait speeds manually or instrumentally assessed is not optimal. The results suggest that manual measures might lead to misclassification of a substantial number of subjects. However, longitudinal studies using standardized and validated procedures aimed at the comparison of different techniques are needed before recommending the use of accelerometers in comprehensive geriatric assessment.
authors.affiliation: Geriatric Rehabilitation Department, University-Hospital of Parma, Parma, Italy.|Department of Clinical and Experimental Medicine, University of Parma, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Maggio
authors.affiliation: Geriatric Rehabilitation Department, University-Hospital of Parma, Parma, Italy.|Department of Clinical and Experimental Medicine, University of Parma, Italy.
authors.forename: Gian Paolo
authors.initials: GP
authors.lastname: Ceda
authors.affiliation: Geriatric Rehabilitation Department, University-Hospital of Parma, Parma, Italy.|Department of Clinical and Experimental Medicine, University of Parma, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Ticinesi
authors.affiliation: Geriatric Rehabilitation Department, University-Hospital of Parma, Parma, Italy.|Department of Clinical and Experimental Medicine, University of Parma, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: De Vita
authors.affiliation: Azienda USL of Parma, Distretto Valli di Taro e Ceno, Parma, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Gelmini
authors.affiliation: Geriatric Rehabilitation Department, University-Hospital of Parma, Parma, Italy.|Department of Clinical and Experimental Medicine, University of Parma, Italy.
authors.forename: Cosimo
authors.initials: C
authors.lastname: Costantino
authors.affiliation: Geriatric Rehabilitation Department, University-Hospital of Parma, Parma, Italy.|Department of Clinical and Experimental Medicine, University of Parma, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Meschi
authors.affiliation: Memory Clinic, University Center for Medicine of Aging Basel (UAB), Felix-Platter Hospital, University of Basel, Switzerland.
authors.forename: Reto W
authors.initials: RW
authors.lastname: Kressig
authors.affiliation: Gérontopôle, Centre Hospitalier Universitaire de Toulouse, Toulouse, France.|Université de Toulouse III Paul Sabatier, Toulouse, France.
authors.forename: Matteo
authors.initials: M
authors.lastname: Cesari
authors.affiliation: General Direction, University-Hospital of Parma, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Fabi
authors.affiliation: Geriatric Rehabilitation Department, University-Hospital of Parma, Parma, Italy.
authors.forename: Fulvio
authors.initials: F
authors.lastname: Lauretani
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005080:Exercise Test / Q000295:instrumentation / Q000379:methods*; D005260:Female; D005684:Gait / Q000502:physiology*; D015577:Geriatric Assessment / Q000379:methods*; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012111:Residence Characteristics; D016138:Walking / Q000502:physiology*