OBJECTIVE. Occupational therapists, as members of early intervention (EI) teams, are responsible for contributing to equitable decision making regarding service eligibility. Because the two editions of the Peabody Developmental Motor Scales (PDMS) are often used in this process, it is important to study these measures. Therefore, the purpose of this study was to examine the implications of using different editions of the PDMS (PDMS versus PDMS-2) and different types of scores (standard deviation versus percent delay) when determining children’s eligibility for EI.
METHOD. With testing order counterbalanced, 30 candidates for EI evaluation, between 11 months and 34 months corrected age, were tested using both the PDMS and the PDMS-2.
RESULTS. Support for EI eligibility often differed depending on the edition of the PDMS used and the type of score used. When the PDMS was used, as opposed to the PDMS-2, disagreements occurred 23% to 43% of the time. For all disagreements, scores on the PDMS supported EI eligibility, whereas scores on the PDMS2 did not. When support for service eligibility was compared using percent delay scores versus standard deviation scores, disagreements occurred more often for the PDMS (Gross Motor: 17%; Fine Motor: 23%) than for the PDMS-2 (Gross Motor: 7%; Fine Motor: 3%).
CONCLUSIONS. It is important that occupational therapists within a facility, and ideally within a state, identify a single test edition to use as part of the process for determining EI eligibility. Also, if standard scores and percent delay scores point to conflicting decisions (eligibility vs. noneligibility), further evaluation and greater reliance on clinical judgment are advised.