Accuracy and Usability of a Self-Administered 6-Minute Walk Test Smartphone Application. (September 2015)

• Record Type: Journal Article
• Authors: Brooks, Gabriel C.; Vittinghoff, Eric; Iyer, Sivaraman; Tandon, Damini; Kuhar, Peter; Madsen, Kristine A.; Marcus, Gregory M.; Pletcher, Mark J.; Olgin, Jeffrey E.
• Is Part Of: Circulation. Volume 8:Number 5(2015)
• Publication Date: 2015-09
• Subjects: Heart failure -- Periodicals; 616.129005
• DOI: 10.1161/CIRCHEARTFAILURE.115.002062
• Languages: English
• ISSNs: 1941-3289

Abstract

<abstract> <title> <x xml:space="preserve">Abstract</x> </title> <sec> <title>Background—</title> <p>The 6-minute walk test (6MWT) independently predicts congestive heart failure severity, death, and heart failure hospitalizations, but must be administered in clinic by qualified staff on a premeasured course. As part of the Health eHeart Study, we sought to develop and validate a self-administered 6MWT mobile application (SA-6MWTapp) for independent use at home by patients.</p> </sec> <sec> <title>Methods and Results—</title> <p>We performed a validation study of an SA-6MWTapp in 103 participants. In phase 1 (n=52), we developed a distance-estimation algorithm for the SA-6MWTapp by comparing step counts from an Actigraph and measured distance on a premeasured 6MWT course with step counts and estimated distance obtained simultaneously from our SA-6MWTapp (best estimation algorithm, r=0.89 [95% confidence interval 0.78–0.99]). In phase 2, 32 participants (including those with congestive heart failure and pulmonary hypertension) used the SA-6MWTapp independently in clinic, and the distance estimated by the SA-6MWTapp was compared with the measured distance (r=0.83 [95% confidence interval 0.79–0.92]). In phase 3, 19 patients with congestive heart failure and pulmonary hypertension consecutively enrolled from clinic performed 3.2±1 SA-6MWTapp tests per week at home over 2 weeks. Distances estimated from the SA-6MWTapp during home 6MWTs were highly repeatable (coefficient of variation =4.6%) and correlated with in-clinic–measured distance (r=0.88 [95% confidence interval 0.87–0.89]). Usability surveys performed during the second (in-clinic) and third (at-home) phases demonstrated that the SA-6MWTapp was simple and easy to use independently.</p> </sec> <sec> <title>Conclusions—</title> <p>An SA-6MWTapp is easy to use and yields accurate repeatable measurements in the clinic and at home.</p> </sec> </abstract>