Exploring communicative competence in autistic children who are minimally verbal: The Low Verbal Investigatory Survey for Autism (LVIS)

Approximately 30% of autistic children are considered minimally verbal. The field lacks an efficient and reliable measure of communicative capacity among minimally verbal autistic children. Improved methods are needed to determine which children are at greatest risk for minimally verbal outcomes to better target interventions. Here, we present the Low Verbal Investigatory Survey (LVIS), a brief parent-report measure designed to assess communicative capacity among minimally verbal autistic children. The 36-item easy-to-complete LVIS was developed to capture the atypical language trajectories associated specifically with autism. We report pilot results from a sample of 147 children (1-8 years) whose caregivers completed the LVIS as part of other studies. Principal components analysis was used to assess dimensionality of the LVIS; composite scores were compared with existing measures of communicative capacity, all of which take significantly more time and training to administer and score. Scores on the LVIS were strongly correlated with existing gold-standard measures of communication. Presence of atypical vocalizations was determined to be particularly relevant for symptoms of autism as well as language and cognitive abilities. These findings provide initial validation of a tool designed to capture multiple dimensions of communicative capacity in children with minimal or low verbal skills. Lay abstract Approximately one in three autistic children is unable to communicate with language; this state is often described as minimally verbal. Despite the tremendous clinical implications, we cannot predict whether a minimally verbal child is simply delayed (but will eventually develop spoken language) or will continue to struggle with verbal language, and might therefore benefit from learning an alternative form of communication. This is important for clinicians to know, to be able to choose the most helpful interventions, such as alternative forms of communication. In addition, the field lacks a standard definition of "minimally verbal." Even when we do agree on what the term means (e.g. fewer than 20 words), describing a child based on their lack of words does not tell us whether that child is communicating in other ways or how they are using those 20 words. To address these concerns, we developed the Low Verbal Investigatory Survey (LVIS), a one-page parent-report measure designed to help us characterize how minimally verbal autistic children are communicating. Parents of 147 children (aged 1-8 years) completed the LVIS. Here, we ask (1) whether the survey measures what it was designed to measure, that is, communicative ability in children without much spoken language, and (2) how the LVIS relates to cognitive and language ability, and symptoms of autism. Results suggest that this survey, which takes only 5 min to complete, is a good estimate of the child's communication skills. Furthermore, LVIS survey scores are correlated with other measures of language and cognitive abilities as well as autism symptomatology. The LVIS has the potential to save time and money in both clinical and research efforts to assess communication skills in minimally verbal autistic children.