title: The 2-min walk test is sufficient for evaluating walking abilities in sporadic inclusion body myositis.
abstract: Sporadic inclusion body myositis causes progressive functional loss due to declining muscle strength. Although the underlying cause is unknown, clinical trials are underway to improve strength and function. Selection of appropriate outcome measures is critical for the success of these trials. The 6-min walk test has been the de facto standard for assessing function in neuromuscular disease; however, the optimal walking test has not been determined in this disease. In this study, 67 individuals with sporadic inclusion body myositis completed a battery of quantitative strength and functional tests including timed walking tests, patient-reported outcomes, and other tasks. The 2-min and 6-min walk tests are highly correlated to each other (r=0.97, p<0.001) and to all lower extremity strength, patient-reported, and functional measures in this population. All subjects completed the 2-min walk test, but 7% of subjects were unable to walk the full 6-min of the 6-min walk test due to fatigue. The 2-min walk test demonstrates similar correlation to all outcomes compared to the 6-min walk test, is less fatiguing and better tolerated. Results suggest that the 2-min walk test is a better alternative to tests of longer duration. Further research is needed to determine longitudinal changes on this outcome.
authors.affiliation: Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, Columbus, OH, United States. Electronic address: lindsay.alfano@nationwidechildrens.org.
authors.forename: L N
authors.initials: LN
authors.lastname: Alfano
authors.affiliation: Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, Columbus, OH, United States.
authors.forename: L P
authors.initials: LP
authors.lastname: Lowes
authors.affiliation: Biostatistics Core, The Research Institute at Nationwide Children's Hospital, Columbus, OH, United States.
authors.forename: I
authors.initials: I
authors.lastname: Dvorchik
authors.affiliation: Biostatistics Core, The Research Institute at Nationwide Children's Hospital, Columbus, OH, United States.
authors.forename: H
authors.initials: H
authors.lastname: Yin
authors.affiliation: Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, Columbus, OH, United States.
authors.forename: E G
authors.initials: EG
authors.lastname: Maus
authors.affiliation: Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, Columbus, OH, United States.
authors.forename: K M
authors.initials: KM
authors.lastname: Flanigan
authors.affiliation: Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, Columbus, OH, United States.
authors.forename: J R
authors.initials: JR
authors.lastname: Mendell
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018979:Myositis, Inclusion Body / Q000503:physiopathology* / Q000628:therapy; D016896:Treatment Outcome; D016138:Walking
keywords: 2-min walk test; 6-min walk test; Function; Outcome measure; Sporadic inclusion body myositis