The aim of this study was to compare the psychometric properties of Alberta Infant Motor Scale (AIMS) with gross motor scale of Peabody Developmental Motor Scale II (PDMS-II) when they were used in high-risk infants.

Fifty-eight high-risk infants with the average age 4.46±0.97 months (from 2 to 6 months) were recruited to this study. Three investigators experienced in AIMS and PDMS-II participated in this study. Each investigator administered the AIMS and PDMS-II to the infants and recorded the assessment results. Forty-seven high-risk infants were followed-up till two years old. The diagnosis at two years old and the first scale assessment result were used to investigate the sensitivity, specificity, positive predictive value and negative predictive value of AIMS and PDMS-II.

When used in high-risk infants in an early age, the AIMS's sensitivity was 0.857, specificity was 0.731, positive predictive value was 0.720, and negative predictive value was 0.864. For the PDMS-II, the sensitivity was 0.524, specificity was 1.000, positive predictive value was 1.000, and negative predictive value was 0.722.

The AIMS is a sensitive monitor tool to evaluate the motor development of high-risk infants at very early age compared with PDMS-II. It needs to dynamic monitor for the high-risk infants.