Motor Function Test Reliability During the NeuroNEXT Spinal Muscular Atrophy Infant Biomarker Study

Area of Science:

• Neurology
• Pediatrics
• Clinical Trials

Background:

• The NeuroNEXT SMA Infant Biomarker Study assessed multi-site rater reliability for infant motor function tests (MFTs) in infants with Spinal Muscular Atrophy (SMA) type 1.
• This longitudinal, multi-center study included infants with SMA type 1 and healthy controls.

Purpose of the Study:

• To evaluate the impact of prospective rater training and rater experience on inter-rater and intra-rater reliability.
• To assess reliability for three specific infant motor function tests: Test of Infant Motor Performance Screening Items (TIMPSI), Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND), and Alberta Infant Motor Scale (AIMS).

Main Methods:

• Raters received training using novel motor function test (MFT) videos to ensure accurate administration and reliability.
• Inter- and intra-rater reliability for TIMPSI, and inter-rater reliability for CHOP-INTEND and AIMS were assessed using intraclass correlation coefficients (ICC).
• The effect of rater experience on reliability was examined using ICC, and agreement with expert consensus scores was evaluated using Pearson's correlation coefficients.

Main Results:

• Good to excellent inter-rater reliability was observed for all MFTs.
• Excellent intra-rater reliability was found for the TIMPSI throughout the study duration.
• Agreement with expert consensus scores met predetermined limits (≥85%) post-training, and evaluator experience did not influence reliability.

Conclusions:

• Reliable and reproducible scores were demonstrated across evaluators for all three MFTs.
• Evaluator experience did not affect the reliability of motor function test scores in this study.
• The findings support the use of these MFTs in multi-center studies involving infants with SMA type 1.