Assessment of upper limb capacity in children with unilateral cerebral palsy: construct validity of a Rasch-reduced
Yvonne Geerdink1, Robert Lindeboom, Sander de Wolf
1Department of Pediatric Rehabilitation, Sint Maartenskliniek, Nijmegen, the Netherlands.
Insights
This study refined the Modified House Classification (MHC) for assessing upper limb function in children with unilateral cerebral palsy (CP). The improved 14-item scale demonstrates good validity for measuring hand capacity.
Area of Science:
- Pediatrics
- Rehabilitation Medicine
- Biostatistics
Background:
- Unilateral cerebral palsy (CP) significantly impacts upper limb function in children.
- Accurate assessment of upper limb capacity is crucial for effective intervention planning.
- The Modified House Classification (MHC) is a tool used for this assessment, but its psychometric properties require refinement.
Purpose of the Study:
- To enhance the unidimensionality and item hierarchy of the Modified House Classification (MHC) using Rasch analysis.
- To evaluate the construct validity of a refined MHC item set for assessing upper limb capacity in children with unilateral CP.
- To improve the measurement properties of the MHC for clinical application.
Main Methods:
- Rasch analysis was applied to 369 videotaped assessments of 159 children with unilateral CP.
- Items were analyzed for unidimensionality and hierarchical structure.
- Construct validity of the Rasch-reduced item set was assessed by correlating scores with the Manual Ability Classification System (MACS) and ABILHAND-Kids scale in 40 additional children.
Main Results:
- Fifteen MHC items were included in the Rasch analysis, with 14 fitting a unidimensional model.
- The Rasch analysis revealed a different item hierarchy compared to the original MHC.
- The refined 14-item MHC demonstrated significant correlations with established measures (MACS: r=-0.901; ABILHAND-Kids: r=0.558).
Conclusions:
- The item hierarchy of the original MHC can be improved for better assessment of upper limb capacity in children with unilateral CP.
- A Rasch-reduced 14-item MHC, utilizing a weighted sum score, exhibits strong construct validity.
- This refined MHC effectively measures the functional capacity of the affected hand in children with unilateral CP.
Aim:
The aim of this study was to test and improve the unidimensionality and item hierarchy of the Modified House Classification (MHC) for the assessment of upper limb capacity in children with unilateral cerebral palsy (CP) using Rasch analysis. The construct validity of the Rasch-reduced item set was evaluated.
Method:
Modified House Classification items were scored from 369 videotaped assessments of 159 children with unilateral CP (98 males, 61 females; median age 6y 6mo, range 2y 1mo-17y 5mo). Construct validity was tested in 40 other children with unilateral CP (21 males, 19 females; median age 8y 2mo, range 3y 3mo-17y 6mo) by comparing total scores with the Manual Ability Classification System (MACS) and the ABILHAND-Kids scale.
Results:
Fifteen MHC items could be included in the Rasch analysis. The excluded items were either too easy or too difficult. Fourteen items fitted the unidimensional model (χ(2) =41.3, df=39, p=0.37). The hierarchy of these items was different from the original MHC. There was a significant correlation with the MACS (r=-0.901, p<0.001) and the ABILHAND-Kids scale (r=0.558, p<0.001).
Interpretation:
The original item hierarchy of the MHC can be improved in order to use its sum score for the assessment of upper limb capacity in children with unilateral CP. The Rasch-reduced 14-item MHC with weighted sum score shows good construct validity to measure functional capacity of the affected hand in children with unilateral CP.
