Reliability and Validity of the TIMPSI for Infants With Spinal Muscular Atrophy Type I

Abstract

Purpose This study examined the reliability and validity of the Test of Infant Motor Performance Screening Items (TIMPSI) in infants with type I spinal muscular atrophy (SMA). Methods After training, 12 evaluators scored 4 videos of infants with type I SMA to assess interrater reliability. Intrarater and test-retest reliability was further assessed for 9 evaluators during a SMA type I clinical trial, with 9 evaluators testing a total of 38 infants twice. Relatedness of the TIMPSI score to ability to reach and ventilatory support was also examined. Results Excellent interrater video score reliability was noted (intraclass correlation coefficient, 0.97–0.98). Intrarater reliability was excellent (intraclass correlation coefficient, 0.91–0.98) and test-retest reliability ranged from r = 0.82 to r = 0.95. The TIMPSI score was related to the ability to reach (P ≤ .05). Conclusion The TIMPSI can reliably be used to assess motor function in infants with type I SMA. In addition, the TIMPSI scores are related to the ability to reach, an important functional skill in children with type I SMA.

Clinical trial of L‐Carnitine and valproic acid in spinal muscular atrophy type I

“…The maximum total TIMPSI score in healthy infants is 99 . The TIMPSI total and subscore reliability at each institution was excellent, as reported previously (0.95–0.99) . Details of testing methodologies and protocols are available from previously published trials and online …”

Baseline results of the NeuroNEXT spinal muscular atrophy infant biomarker study

“…All subjects were evaluated using the Test of Infant Motor Performance Screening Items (TIMPSI), a 29‐item, 99 point scale evaluation of infant motor function that has been shown to be valid and reliable in infants with SMA type 1 23. After testing, all subjects were required to have a 20‐minute rest period that could include nursing/feeding.…”

Developmental milestones in type I spinal muscular atrophy

“…A few attempts have been made recently to develop clinical tools specifically designed to assess motor function in weak infants, such as the CHOP INTEND [6], or to adapt existing scales, such as the TIMP [7], [8]. These scales have helped us to identify the variability of the phenotype and to assess the rapid progression of the disease.…”