Interobserver agreement of the Gross Motor Function Classification System in an ambulant population of children with cerebral palsy

Abstract

Gross Motor Function Classification System (GMFCS) level was reported by three independent assessors in a population of children with cerebral palsy (CP) aged between 4 and 18 years (n=184; 112 males, 72 females; mean age 10y 10mo [SD 3y 7mo]). A software algorithm also provided a computed GMFCS level from a regional CP registry. Participants had clinical diagnoses of unilateral (n=94) and bilateral (n=84) spastic CP, ataxia (n=4), dyskinesia (n=1), and hypotonia (n=1), and could walk independently with or without the use of an aid (GMFCS Levels I-IV). Research physiotherapist (n=184) and parent/guardian data (n=178) were collected in a research environment. Data from the child's community physiotherapist (n=143) were obtained by postal questionnaire. Results, using the kappa statistic with linear weighting (κ κ lw ), showed good agreement between the parent/guardian and research physiotherapist (κ κ lw =0.75) with more moderate levels of agreement between the clinical physiotherapist and researcher (κ κ lw =0.64) and the clinical physiotherapist and parent/guardian (κ κ lw =0.57). Agreement was consistently better for older children (>2y). This study has shown that agreement with parent report increases with therapists' experience of the GMFCS and knowledge of the child at the time of grading. Substantial agreement between a computed GMFCS and an experienced therapist (κ κ lw =0.74) also demonstrates the potential for extrapolation of GMFCS rating from an existing CP registry, providing the latter has sufficient data on locomotor ability.In 1997 Palisano et al. 1 presented an alternative approach to the classification of cerebral palsy (CP) with publication of the Gross Motor Function Classification System (GMFCS). Based upon the concepts of disability and functional limitation as laid out by the World Health Organization, 2 it classifies children on the level of their motor ability. It is represented by a 5-point ordinal scale in which the higher the level, the less able the child. It is now used extensively in developmental research and clinical practice, 3 and its relation with measures of gait, 4,5 energy efficiency, 4,6 participation restriction, 7 and health-related quality of life [8][9][10] in the population with CP has been explored. Although increasing numbers of papers lend weight to the validity of the GMFCS, 1,4,11,12 very few papers have explored the reliability of the classification system. Palisano et al.'s landmark paper 1 demonstrated good interrater reliability (κ=0.75) between all five GMFCS levels in 40 children with CP aged 2 to 12 years. A subsequent study demonstrated excellent interrater reliability between a developmental paediatrician and a senior physiotherapist using retrospective chart review. 13 In two recent studies 14,15 a concise questionnaire, used to obtain family report of GMFCS level, demonstrated excellent reliability with that assigned by various health professionals.So far, no study has reported the feasibility of assigning a child with CP to a GMFCS level using data it...

Confiabilidade do Sistema de Classificação da Função Motora Grossa Ampliado e Revisto (GMFCS E & R) entre estudantes e profissionais de saúde no Brasil

“…Indexes of agreement quite similar to the students' group of this research (Group 3) were obtained in other studies, but with more experienced professionals 8,10,12,23 . The study of Kondo et al 10 involved professionals from different areas (physical therapists, occupational therapists, speech therapists, doctors, and nurses) who made direct observation of the child, with kappa of 0.66.…”

“…In this study, we found substantial agreement among students (Group 3) or professionals of the same area, with up to two years of experience (Group 2), when they classified the motor level of children using the Brazilian version of the GMFCS E&R. In most studies, the agreement in the classification of the GMFCS has also been substantial, with kappa coefficient raging between 0.64 and 0.80 4,9,12 , involving different health professionals (physical therapists 4,10,12,14,17 , doctors 8,9,10,17 , occupational therapists 4,5 , speech therapists 10 , and nurses 10 ) and different methods of collecting information to classify the gross motor function using the GMFCS or GMFCS E & R (direct observation 4,8,9,12,16 , questioning of parents 12,16 , review of medical records 7,8,23 ). Indexes of agreement quite similar to the students' group of this research (Group 3) were obtained in other studies, but with more experienced professionals 8,10,12,23 .…”

“…The study of Kondo et al 10 involved professionals from different areas (physical therapists, occupational therapists, speech therapists, doctors, and nurses) who made direct observation of the child, with kappa of 0.66. The study of McDowell et al 12 involved two physical therapists and direct observation of the child was also held associated with the questioning of the parents, with kappa of 0.64.…”

“…The GMFCS E&R translation into Brazilian Portuguese made in accordance with the ones suggested by Center For Childhood Disability Research (CanChild) and made available on their website * was conducted in 2010 by a group of occupational therapists and one neurologist 7 . The validity and reliability of the original version of the GMFCS have been extensively studied and well established among health professionals in different countries (physical therapists, pediatricians, orthopedists, physiatrists, and occupational therapists) 6,8,9,10 , and parents 8,[11][12][13][14][15] , which is also beginning to occur with the extended and revised version (GMFCS E&R) 16 . The GMFCS can easily be incorporated into clinical practice, allowing comparisons of children accompanied by different clinicians with similar functional levels, and also can predict the gross motor function of children with cerebral palsy 17 .…”

The Reliability and Concurrent Validity of the GMFCS for Children with Cerebral Palsy

“…Based upon the concepts of disability and functional limitation as laid out by the World Health Organization, it classifies children by the level of their motor ability. It is presented as a 5-point ordinal scale in which the higher the level, the less able the child 2) . Formal CP classification methods, such as the GMFCS, have been developed in order to standardize the clinical variability, which is one of the major characteristics of CP 3) .…”