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Published on: June 20, 2020
Validity of the Peabody Developmental Gross Motor Scale as an evaluative measure of infants receiving physical
R J Palisano1, T H Kolobe, S M Haley
1Department of Physical Therapy (Mail Stop 502), Medical College of Pennsylvania, Philadelphia, PA, USA.
Insights
The Peabody Developmental Gross Motor Scale (PDMS-GM) shows some validity for infants in physical therapy. However, it may not be sensitive enough to detect changes in motor development for all infants, especially those with cerebral palsy.
Area of Science:
- Pediatric physical therapy
- Developmental motor assessment
- Infant clinical research
Background:
- The Peabody Developmental Gross Motor Scale (PDMS-GM) is frequently used to assess motor skills in infants.
- Its utility as an evaluative tool for infants undergoing physical therapy requires further validation.
Purpose of the Study:
- To determine the validity and responsiveness of the PDMS-GM for infants receiving early intervention physical therapy.
- To assess if the PDMS-GM can reliably detect changes in gross motor function over time.
Main Methods:
- A cohort of 124 infants (N=124) from an early intervention program, grouped by diagnosis (e.g., cerebral palsy, Down syndrome, developmental delay), were assessed.
- The PDMS-GM was administered three times over six months by an independent therapist.
Main Results:
- Infants across all diagnostic groups showed increases in mean scaled and age-equivalent scores.
- The reliable change index indicated that 62% of infants experienced changes exceeding measurement error.
- The index of responsiveness was 0.5, suggesting a need for 68 subjects per group in research studies.
Conclusions:
- While mean score changes support the PDMS-GM's use as an evaluative measure, its responsiveness is limited for some infants, particularly those with cerebral palsy.
- The PDMS-GM is best suited as a global measure of motor development in large clinical trials rather than for evaluating direct physical therapy effects.
Background And Purpose:
The purpose of this study was to examine the validity of the Peabody Developmental Gross Motor Scale (PDMS-GM) as an evaluative measure of infants receiving physical therapy.
Subjects And Methods:
Infants who attended an early intervention program (N = 124) were grouped by diagnosis: cerebral palsy, Down syndrome, hydrocephalus, preterm with developmental delay, full term with developmental delay, and other. The PDMS-GM was administered to each infant three times over a 6-month period by a therapist who did not provide treatment.
Results:
Mean scaled scores and age-equivalent scores increased for each group. Individual change was examined using the reliable change index. The results indicated that the change in total raw score for 62% of the infants was greater than what could be attributed to measurement error. When minimal clinically important change was defined as 10 scaled score points, the index of responsiveness was equal to 0.5. This finding indicates that a sample size of 68 subjects per group would be needed when the PDMS-GM is used as an outcome measure in research.
Conclusion And Discussion:
The mean change scores for each group support the use of the PDMS-GM as an evaluative measure. For many infants, particularly infants with cerebral palsy, the PDMS-GM was not responsive to change over a 6-month period. The index of responsiveness suggests that the PDMS-GM should be used only as an outcome measure in large clinical trials. The PDMS-GM is not recommended for evaluating the direct effects of physical therapy but is recommended for providing a global measure of change in motor development as part of a multidimensional assessment.
