Canadian and Brazilian Percentile Ranks for the Alberta Infant Motor Scale.

To verify if there is a difference between the percentile ranks for Brazilian infants compared with norms for Canadian infants on the Alberta Infant Motor Scale (AIMS). A cross-sectional study in which 322 Brazilian infants, 2 to 15 months old, were administered the AIMS. Percentile ranks were calculated using norms for Canadian infants and norms from two studies of Brazilian infants. The Friedman test compared the AIMS percentile ranks for the entire sample. For reliability analysis, the interclass correlation coefficient (ICC) was used. Bland Altman's analysis was applied to compare percentile ranks. Of the 322 evaluations analyzed, there were significant differences (p<.001) between the three percentile ranks compared. The Canadian norms presented the lowest average rating. There was good reliability between the percentile ranks (ICC > 0.75) but low agreement (Bland Altman; p<.001). There are differences between the Brazilian and Canadian percentile ranks and between the Brazilian percentile ranks of 2014 and 2016, and these differences may influence identification of motor development.