Development of a tool to assess visual attention in Rett syndrome: a pilot study.

This was a two-phase study that aimed to (a) develop a tool for assessing visual attention in individuals with Rett syndrome using AAC with a communication partner during naturalistic interactions in clinical settings; and (b) explore aspects of the tool's reliability, validity, and utility. The Assessment of Visual Attention in Interaction (AVAI) tool was developed to assess visual attention operationalized as focused gazes (1 s or longer) at the communication partner, an object, and a symbol set. For the study, six video-recorded interactions with nine female participants diagnosed with Rett syndrome (range: 15-52-years-old) were used to calculate intra- and inter-rater agreement, and 18 recorded interactions were analyzed to examine sensitivity to change and acceptability. There was a significant difference in the AVAI results between two conditions (with and without aided-language modeling). Inter-rater agreement ranged from moderate and strong. There was a range in scores, indicating that the AVAI could differentiate between participants. The AVAI was found to be reliable, able to detect change, and acceptable to the participants. This tool could potentially be used for evaluating interventions that utilize aided AAC.