The intra- and inter-rater reliability of component analysis of rise from supine in the children with typical development and developmental delay

The purpose of this study was to determine the intra- and inter-rater reliability of classifying the movement patterns of rising from supine to stand in the children with typical development (TD) and mild to moderate developmental delay (DD). Sixty-eight children with TD and 20 children with DD aged 2 through 6 years were videotaped during rising. Two trained pediatric physical therapists independently viewed each videotape and classified the movement patterns of upper extremities (UE), trunk/axial (AX) and lower extremities (LE) regions using descriptive categories developed by previous researchers. Kappa statistic and average percentage of agreement were calculated to determine reliability. The average agreement rate of intra-rater ranged from 90% to 97% in TD group for three regions, and 79% to 89% in DD group; the agreement rate between raters ranged from 82% to 95% in TD group for three regions, and 71% to 87% in DD group. Using kappa statistic guidelines, high intra- and inter-rater reliabilities (k > 0.81) were found in TD group, except inter-rater reliability for LE. Substantial intra- and inter-reliabilities (0.61 < k < 0.81) were found in DD group. As comparing the reliabilities of three regions, the lowest intra- and inter-rater reliabilities were found at the LE region in both groups. As taking age into consideration and dividing each group into subgroups by 2-year interval, in DD group, the intra-rater reliabilities were higher in younger participants (aged 2-4 years), except for the LE region, but the results of inter-rater reliabilities were variable. For the children with TD, the levels of inter-rater reliability increased for the UE region and decreased for LE region in older age, but the results for these two regions were reverse for the children with DD. The findings of this study suggested that the complexities and difficulties affecting reliabilities in classifying the movement patterns of rising were related to developmental capability, age and body region. In order to improve intra- and inter-rater reliabilities, extra training is needed in examining the children with DD, particularly for the UE and LE regions.