Simplified methods for identifying subtypes of automatically maintained self-injury

Subtypes of automatically maintained self-injurious behavior (SIB) have been defined based on response patterns observed during the functional analysis, which are thought to reflect each subtype's distinct mechanisms. Current practice for identifying subtypes involves using structured criteria to identify whether SIB is automatically maintained, followed by the application of additional criteria to identify the subtype. We describe a series of studies directed at simplifying these methods to facilitate wider application of the subtyping model in research and practice. In Studies 1 and 2, we demonstrate the accuracy of modified criteria using the level of differentiation of SIB across the play and no-interaction conditions at distinguishing between two subtypes (i.e., Subtypes 1 and 2). We then demonstrate visual analysis (without structured criteria) can accurately identify SIB as automatically maintained in Study 3, which can be used in combination with level of differentiation to enable application of the subtyping model in practice.