Concurrent Validity of the Bayley-III and the Peabody Developmental Motor Scales-2 at 18 Months

Abstract

Aim: To determine concurrent validity between the Bayley Scales of Infant and Toddler Development, 3^rd edition (Bayley-III) and the Peabody Developmental Motor Scales, 2^nd edition (PDMS-2). Methods: Both assessments were administered to 184 preterm children at 18 months corrected age; standard scores for total score, gross motor, and fine motor were calculated for each child. Cross-tabulation and Pearson correlation coefficient (r) determined concurrent validity between the Bayley-III and the PDMS-2 motor domains. Results: High correlations were found between total motor (r = 0.88), gross motor (r = 0.88), and fine motor scores (r = 0.79). Both assessments had 93% agreement on classification for motor impairment; 23 children were identified by both assessments as having motor impairments, but 12 children were identified differently on each assessment (7 as impaired on PDMS-2 but average on Bayley-III; 5 as impaired on Bayley-III but average on PDMS-2). Most children with motor impairments were identified as 1SD below the mean on the PDMS-2 (27/30) and Bayley-III (18/28); however, the Bayley-III identified more children 2SD below the mean (10/28) compared to the PDMS-2 (3/30). Conclusions: Both the Bayley-III and PDMS-2 identify motor delays in children; however, clinicians should be aware of the concurrent validity as each assessment may lead to differing results.

Keywords:

• Bayley-III
• concurrent validity
• motor assessment
• PDMS-2
• preterm infants

Acknowledgments

We thank the children and families who participated in this study and physical therapists, Sarah Wright, Marilyn Rogers, and Kathy Couture, who contributed to the administration of the assessments.

Additional information

Funding

This study was funded by the Canadian Institutes of Health Research (CIHR) grants (MOP 79262 PI Miller and MOP 86489 PI Grunau). Gill is funded by a CIHR Master’s Scholarship. Grunau is funded by a salary award BC Children’s Hospital Research Institute. Miller is supported by the Bloorview Children’s Hospital Chair in Paediatric Neuroscience. Zwicker is funded by the Michael Smith Foundation for Health Research, Canadian Child Health Clinician Scientist Program, BC Children’s Hospital Research Institute, Sunny Hill Foundation, and CIHR.