6th vital sign app: Testing validity and reliability for measuring gait speed

E Martin; S Kim; A Unfried; S Delcambre; N Sanders; B Bischoff; R Saavedra

doi:10.1016/j.gaitpost.2018.12.005

6th vital sign app: Testing validity and reliability for measuring gait speed

Gait Posture. 2019 Feb:68:264-268. doi: 10.1016/j.gaitpost.2018.12.005. Epub 2018 Dec 5.

Authors

E Martin¹, S Kim², A Unfried³, S Delcambre⁴, N Sanders⁵, B Bischoff⁶, R Saavedra⁷

Affiliations

¹ Kinesiology Department, California State University, Monterey Bay, 100 Campus Center, Seaside, CA, 93955, USA. Electronic address: ermartin@csumb.edu.
² Mathematics and Statistics Department, California State University, Monterey Bay, 100 Campus Center, Seaside, CA, 93955, USA. Electronic address: stkim@csumb.edu.
³ Mathematics and Statistics Department, California State University, Monterey Bay, 100 Campus Center, Seaside, CA, 93955, USA. Electronic address: aunfried@csumb.edu.
⁴ Kinesiology Department, California State University, Monterey Bay, 100 Campus Center, Seaside, CA, 93955, USA. Electronic address: sdelcambre@csumb.edu.
⁵ Mathematics and Statistics Department, California State University, Monterey Bay, 100 Campus Center, Seaside, CA, 93955, USA. Electronic address: nsanders@csumb.edu.
⁶ Kinesiology Department, California State University, Monterey Bay, 100 Campus Center, Seaside, CA, 93955, USA. Electronic address: bbischoff@csumb.edu.
⁷ Kinesiology Department, California State University, Monterey Bay, 100 Campus Center, Seaside, CA, 93955, USA. Electronic address: rsaavedra@csumb.edu.

PMID: 30551051
DOI: 10.1016/j.gaitpost.2018.12.005

Abstract

Background: Gait speed tests are useful predictors of different health outcomes in people. These tests can be administered by the convenience of one's smartphone.

Research question: Is the 6th Vital Sign app valid and reliable for measuring gait speed?

Methods: The study used a prospective test-retest design. Fifteen college subjects were asked to walk at their normal pace for 2 min. Each subject performed two trials. Speed was recorded by the 6th Vital Sign app, Brower timing gates, and by hand-measurement of distance walked divided by the 2 min. Criterion validity was assessed by paired t-tests, Cohen's D effect sizes, and Pearson correlation tests. Inter-trial reliability within each device was assessed with Pearson correlation tests.

Results: Speed measured by the app was significantly lower than speed measured by gates (p = 0.004) and by hand-measurement (p = 0.009). The difference between gates and hand-measurement was not significant (p = 0.684). The speed measured by gates and hand-measurement were very highly correlated (r = 0.974), but speed measured by app was only moderately correlated with gates (r = 0.370) and hand-measurement (r = 0.365). The inter-trial reliability was fairly high with correlations r = 0.916, 0.944, and 0.941 when speed was measured by the app, gates, and hand-measurement, respectively.

Significance: The app tended to underestimate speed when compared to gate and hand-measurements. Therefore, we conclude that the 6^th Vital Sign app is not valid for use for clinical diagnosis or prognosis.

Keywords: Fitness testing; Gait speed; Health screening; Morbidity; Risk assessments.

Publication types

Evaluation Study
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Adult
Female
Gait / physiology*
Humans
Male
Middle Aged
Mobile Applications / standards*
Outcome Assessment, Health Care / methods*
Physical Fitness / physiology*
Prospective Studies
Reproducibility of Results
Smartphone*
Walking Speed / physiology*