Outcome assessments in children with cerebral palsy, part II: discriminatory ability of outcome tools
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Measuring the Functional Abilities of Children Aged 3-6 Years Old with Observational Methods and Computer Tools
Published on: June 20, 2020
Anita M Bagley1, George Gorton, Donna Oeffinger
1Shriners Hospital for Children, Northern California Motion Analysis Laboratory, Sacramento, CA 95817, USA. abagley@shrinenet.org
Insights
The Gross Motor Function Measure (GMFM) and WeeFIM Mobility best differentiate cerebral palsy severity across Gross Motor Function Classification System (GMFCS) levels I-III. Other tools show varying discrimination, with QoL and cognition measures being least discriminatory but still vital.
Area of Science:
- Pediatric rehabilitation
- Clinical assessment tools
- Cerebral palsy research
Background:
- Cerebral palsy (CP) classification systems are crucial for understanding functional abilities.
- Assessing the discriminatory power of various outcome measures relative to the Gross Motor Function Classification System (GMFCS) is essential for accurate patient stratification.
- Pediatric outcome tools need validation for their ability to detect differences across functional levels in children with CP.
Purpose of the Study:
- To evaluate the discriminatory ability of multiple pediatric outcome tools across Gross Motor Function Classification System (GMFCS) levels in patients with cerebral palsy (CP).
- To identify the most sensitive and specific measures for distinguishing between different GMFCS levels (I to III) in a pediatric CP population.
- To compare the effectiveness of various functional and quality-of-life measures in reflecting motor function severity in CP.
Main Methods:
- A prospective, multicenter, cross-sectional study involving 562 pediatric patients with CP (GMFCS Levels I-III).
- Data collection included parent and participant completion of various outcome tools, alongside objective measures like gait velocity and cadence.
- Statistical analyses employed effect size indices (ESIs) and odds ratios for discrimination, with logistic regression and ROC curves for sensitivity and specificity.
Main Results:
- The Gross Motor Function Measure (GMFM-66) and WeeFIM Mobility demonstrated strong discrimination between GMFCS Levels I and II.
- Between GMFCS Levels II and III, GMFM Dimension E, WeeFIM Self-Care and Mobility, and Gillette Functional Assessment Questionnaire Question 1 showed significant discriminatory power.
- Pediatric Outcomes Data Collection Instrument (PODCI) measures (Sports & Physical Function, Global Function) exhibited large ESIs across all GMFCS level comparisons.
Conclusions:
- The GMFM and WeeFIM are highly effective in discriminating functional levels in pediatric CP patients across GMFCS I-III.
- While QoL and cognition measures showed less discrimination, they remain important for a holistic assessment of treatment impact.
- Specific subscales of the PODCI also offer valuable discriminatory information for assessing functional status in CP.
Abstract:
Discriminatory ability of several pediatric outcome tools was assessed relative to Gross Motor Function Classification System (GMFCS) level in patients with cerebral palsy. Five hundred and sixty-two patients (400 with diplegia, 162 with hemiplegia; 339 males, 223 females; age range 4-18y, mean 11y 1mo [SD 3y 7mo]), classified as GMFCS Levels I to III, participated in this prospective multicenter, cross-sectional study. All tools were completed by parents and participants when appropriate. Effect size indices (ESIs) for parametric variables and odds ratios for non-parametric data quantified the magnitude of differences across GMFCS levels. Binary logistic regression models determined discrimination, and receiver operating characteristic curves addressed sensitivity and specificity. Between Levels I and II, the most discriminatory tools were Gross Motor Function Measure (GMFM-66), velocity, and WeeFIM Mobility. Between Levels II and III, the most discriminatory tools were GMFM Dimension E, Pediatric Functional Independence Measure (WeeFIM) Self-Care and Mobility, cadence, and Gillette Functional Assessment Questionnaire Question 1. Large ESIs were noted for Parent and Child reports of Pediatric Outcomes Data Collection Instrument (PODCI) Sports & Physical Function, Parent report of PODCI Global Function, GMFM Dimension E, and GMFM-66 across all GMFCS level comparisons. The least discriminatory tools were the Quality of Life and cognition measures; however, these are important in comprehensive assessments of treatment effects.
