Criterion validity of the GMFM‐66 item set and the GMFM‐66 basal and ceiling approaches for estimating GMFM‐66 scores. (1st March 2013)

• Record Type: Journal Article
• Authors: Avery, Lisa M; Russell, Dianne J; Rosenbaum, Peter L
• Is Part Of: Developmental medicine & child neurology. Volume 55:Number 6(2013:Jun.)
• Page Start: 534
• Page End: 538
• Publication Date: 2013-03-01
• Subjects: Child development -- Periodicals; Pediatric neurology -- Periodicals; 616.8
• DOI: 10.1111/dmcn.12120
• Languages: English
• ISSNs: 0012-1622

Abstract

<abstract abstract-type="main" xml:lang="en" id="dmcn12120-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="dmcn12120-sec-0001" sec-type="section"> <title>Aim</title> <p>The aim of this study was to compare the accuracy of two abbreviated approaches for estimating Gross Motor Function Measure 66 (GMFM‐66) scores against the full GMFM‐66 and to explore their strengths and limitations.</p> </sec> <sec id="dmcn12120-sec-0002" sec-type="section"> <title>Method</title> <p>An existing dataset (<italic>n</italic>=224) comprising children aged 1 to 13 years (mean age 6y 11mo, SD 4y 6mo; 132 males, 92 females) with cerebral palsy (CP) of all Gross Motor Function Classification System (GMFCS) levels was used to compare the validity of the item set version (GMFM‐66‐IS) and the basal and ceiling version (GMFM‐66‐B&C) with the full GMFM‐66 scores. Follow‐up assessment at 1 year (<italic>n</italic>=109) allowed evaluation of change scores and accuracy at a single point in time.</p> </sec> <sec id="dmcn12120-sec-0003" sec-type="section"> <title>Results</title> <p>The cross‐sectional agreement was excellent for both abbreviated measures (all intraclass correlation coefficients [ICCs] >0.98). When measuring change over time, both the GMFM‐66‐IS and the GMFM‐66‐B&C showed good agreement for children with bilateral CP (ICCs >0.9). However, the GMFM‐66‐IS assessed change over 1 year more accurately than the GMFM‐66‐B&C in children with unilateral CP (ICC=0.89 vs ICC=0.58; 95% confidence intervals do not overlap).</p> </sec> <sec id="dmcn12120-sec-0004" sec-type="section"> <title>Interpretation</title> <p>Both approaches for estimating GMFM‐66 scores are accurate at a single point in time. If the primary goal of assessment is to measure change, the full GMFM‐66 should still be regarded as the criterion standard. The GMFM‐66‐IS should be the preferred shortened measure for children with unilateral CP.</p> </sec> </abstract>