Concurrent validity of the Bayley Scales of Infant Development II (BSID-II) Motor Scale and the Peabody Developmental Motor Scale II (PDMS-2) in 12-month-old infants.

PURPOSE: This study was designed to examine concurrent validity of the Peabody Developmental Motor Scale II (PDMS-2) and the Bayley Scales of Infant Development II (BSID-II) Motor Scale.

METHODS

The PDMS-2 and the BSID-II Motor Scale were administered to fifteen 12-month-old infants who were developing typically. PDMS-2 raw scores were converted to the Gross Motor Quotient (GMQ), the Fine Motor Quotient (FMQ), and the Total Motor Quotient (TMQ). BSID-II raw scores were converted to the Psychomotor Development Index (PDI). Age equivalent scores were obtained for all PDMS-2 Gross and Fine Motor Subscales and for the BSID-II Motor Scale and compared using the Pearson Product-Moment Correlation Coefficient.

RESULTS

Low correlations were found between the PDMS-2 FMQ, GMQ, TMQ, and the PDI of the BSID-II. Low correlations were found between age equivalent scores of the PDMS-2 subtests for grasp, stationary, and Visual Motor Integration and the BSID-II Motor Scale. A low negative correlation was found between age equivalent scores of the PMDS-2 subtest for Object Manipulation and the BSID-II Motor Scale. A high correlation (r = 0.71, P < 0.05) was found between age equivalent scores of the PDMS-2 subtest for locomotion and the BSID-II Motor Scale.

CONCLUSIONS

There is a lack of concurrent validity between the PDMS-2 standard scores and standard scores of the BSID-II Motor Scale and a lack of agreement between age equivalent scores of the BSID-II Motor Scale and the PDMS-2 subtests except for Locomotion. The investigators caution about using only one standard score or age equivalent score for decisions about the need for early intervention for children at 12 months of age when using the BSID-II or the PDMS-2.