Additional file 1 of Longitudinal change in restricted and repetitive behaviors from 8-36 months

Additional file 1: Figure S1. Sample distribution (n=606) for total items endorsed (Mean=8.79, SD=6.2). Table S1. Median item-level responses (min=0, max=4). Each item was converted to a binary scale (0, 1) using its median split. These binarized scores were then used to calculate the proportion of samples endorsing a given item. Table S2. Linear Mixed Effects Model results testing the effect of Age, Cohort, and Sex on Repetitive Motor raw mean scores. Model 1=Baseline model; Model 2=Establishing functional form; Linear fixed and random effects of age. Model did not converge when covariates (Cohort and Sex) were included, and was not considered as a candidate model, so Model 2 was adopted as final model. Table S3. Linear Mixed Effects Model results testing the effect of Age, Cohort, and Sex on Self-directed raw mean scores. Model 1=Baseline model; Model 2=Establishing functional form; Linear fixed effects of age. Model 3=Assessing covariates. Model 4=Final model with significant covariate of Cohort included. Table S4. Linear Mixed Effects Model results testing the effect of Age, Cohort, and Sex on Higher-order raw mean scores. Model 1=Baseline model. Model 2=Adding covariates (initial model establishing functional form found no significant fixed or random effects of Age). Model 3=Final model selected after removing non-significant effects of Sex and Cohort.