Objectives: This study systematically investigated behavioural and physiological effects of weighted vests for preschool and elementary school-aged children with autism.
Methods: Participants included ten children with autism, ages 3 to 10, in a classroom setting. All participants had low or limited language skills, significant cognitive impairment, and required an individual aide to participate in school activities. A single-case, ABCBC design was used where A =behavioural baseline without vest or heart rate monitor; B = vest with sham (unweighted) weights and heart rate monitor; C = vest with 5-10% body weighted and heart rate monitor. Observers, blinded to treatment condition, rated targeted behaviours for each participant through video taken during structured table-top activities typical of the classroom routine. Targeted behaviours included off-task and stereotyped behaviours and sitting. Visual analysis supported by percent non-overlapping data statistics was used to evaluate treatment effects. Teachers, also blinded to treatment condition, rated each child’s behaviour with the Conners’ Global Index following each phase of the study. Educational aides, not blinded to treatment condition, provided subjective feedback about the effects of the weighted vest for each participant. Social validity was reported by teachers and educational aides. Heart rate was collected when participants wore the vest.
Results: Objective results suggest that weighted vests were minimally to moderately effective (visual analysis and PND = 70%) in decreasing off-task behaviour in 3 participants, and possibly 2 additional participants for whom potential confounds precluded our ability to confidently say the effects were due to the vest. Weighted vests were not effective in decreasing motoric stereotyped behaviours or improving a child’s ability to stay seated. Heart rate did not decrease with the weighted vest. Subjectively, all aides, who were not blinded to treatment condition, reported that weighted vests were effective in improving behaviour in all participants. All teachers and aides reported that weighted vests were appropriate modalities to use in the classroom and wanted to continue using weighted vests following the study.
Conclusions: Contrary to subjective reports, there was limited objective support for weighted vests to decrease off-task behaviour in children with autism in the classroom setting. Weighted vest use was not supported for motoric stereotyped behaviours or sitting. The theoretical basis for weighted vest use was not supported as measured here. Although weighted vests may be an appropriate modality to include as a component of intervention with some children with autism, results were not strong for any participant or consistent across participants. Therefore, if weighted vests are recommended, outcomes must be systematically evaluated. Weighted vests should not be used in isolation to improve classroom function in children with autism.