Minimum Clinically Important Difference of Gross Motor Function and Gait Endurance in Children with Motor Impairment: A Comparison of Distribution-Based Approaches.

Fabio Alexander Storm,Emilia Biffi,Gianluigi Reni,Enrico Castelli,Giampietro Cordone,Claudio Corbetta,Alessandra Colazza,Maurizio Petrarca,Sandra Strazzer,Flaminia Frascarelli,Cristina Maghini,Daniele Panzeri,Luigi Piccinini,Roberta Morganti,Elena Beretta

doi:10.1155/2020/2794036

Abstract

Objective The minimum clinically important difference (MCID) is a standard way of measuring clinical relevance. The objective of this work was to establish the MCID for the 6-minute walking test (6minWT) and the Gross Motor Function Measure (GMFM-88) in pediatric gait disorders. Methods A cohort, pretest-posttest study was conducted in a hospitalized care setting. A total of 182 patients with acquired brain injury (ABI) or cerebral palsy (CP) performed 20 robot-assisted gait training sessions complemented with 20 sessions of physical therapy over 4 weeks. Separate MCIDs were calculated using 5 distribution-based approaches, complemented with an anonymized survey completed by clinical professionals. Results The MCID range for the 6minWT was 20-38 m in the ABI cohort, with subgroup ranges of 20-36 m for GMFCS I-II, 23-46 m for GMFCS III, and 24-46 m for GMFCS IV. MCIDs for the CP population were 6-23 m, with subgroup ranges of 4-28 m for GMFCS I-II, 9-19 m for GMFCS III, and 10-27 m for GMFCS IV. For GMFM-88 total score, MCID values were 1.1%-5.3% for the ABI cohort and 0.1%-3.0% for the CP population. For dimension “D” of the GMFM, MCID ranges were 2.3%-6.5% and 0.8%-5.2% for ABI and CP populations, respectively. For dimension “E,” MCID ranges were 2.8%-6.5% and 0.3%-4.9% for ABI and CP cohorts, respectively. The survey showed a large interquartile range, but the results well mimicked the distribution-based methods. Conclusions This study identified for the first time MCID ranges for 6minWT and GMFM-88 in pediatric patients with neurological impairments, offering useful insights for clinicians to evaluate the impact of treatments. Distribution-based methods should be used with caution: methods based on pre-post correlation may underestimate MCID when applied to patients with small improvements over the treatment period. Our results should be complemented with estimates obtained using consensus- and anchor-based approaches.

Highlights

Cerebral palsy (CP) and acquired brain injury (ABI) are commonly associated with gait disorders [1, 2]
For GMFM-88, our study reports GMFM-88 total score minimum clinically important difference (MCID) values ranging between 1.1% and 5.3% for the overall ABI cohort, while for the CP population the MCID range was 0.1% to 3.0%
To the best of our knowledge, this is the first study providing a range of values that could serve as reference for clinicians in order to establish a therapeutic threshold for the 6-minute walking test (6minWT) and the GMFM-88 for a pediatric population affected by gait disorders after one month of robotic gait rehabilitation

Summary

Introduction

Cerebral palsy (CP) and acquired brain injury (ABI) are commonly associated with gait disorders [1, 2]. Traumatic brain injury is the most frequent cause of ABI, while nontraumatic ABI, such as stroke and tumor, have lower incidence [3]. In both CP and ABI, rehabilitation medicine and physical therapy programs play a crucial role in the multidisciplinary approach representing the gold standard of care [4, 5]. RAGT systems impose a regular gait pattern while allowing a degree of body-weight support in combination with proper alignment of the lower limbs [6]

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Results

Discussion

Conclusion