Measure of Interactive Strategy Implementation – Caregivers (MISI-C): Preliminary Validity and Reliability

Background: Early interventions for ASD use Parent Mediated Intervention (PMI) to teach parents interactive strategies targeting social communication in their children with ASD (Kasari et al., 2014; Pickles et al., 2016; Wetherby et al., 2014). Although individual treatments have attempted to use specific fidelity ratings to measure caregiver strategy implementation (Gulsrud et al., 2016; Rogers et al., 2018), there is no uniform measurement that can be used to examine caregiver strategies across different PMIs. This study provides initial validity and reliability of the Measure of Interactive Strategy Implementation-Caregivers (MISI-C), a novel outcome measure designed to capture changes in caregiver implementation of interactive strategies for toddlers with ASD over the course of various early interventions.

Objectives: We aim to (1) determine items for inclusion in the final MISI-C coding scheme, (2) explore the factor structure of the MISI-C items, (3) examine inter-rater (IRR) and test-retest (TRT) reliability, and (4) provide initial evidence for validity of the MISI-C in capturing changes in caregivers’ strategy implementation during intervention and how those changes are associated with changes in children’s social communication.

Methods: The MISI-C was applied to 116 observations of 43 caregiver-child dyads with minimally verbal children ranging from 1-5 years of age with varying language, cognitive, and ASD symptoms. All caregiver-child dyads participated in various PMIs (Kasari et al., 2010; Rogers et al., 2012; Wetherby et al., 2014) and were observed at two time points, on average 6 months apart. We constructed items in the MISI-C based on the interactive strategies commonly taught across different Naturalistic Developmental Behavioral Intervention ([NDBIs]; Schreibman et al., 2015). An Exploratory Factor Analysis (EFA) was conducted to determine statistically related domains of core strategies. Intraclass correlations (ICCs) were used for IRR and TRT reliability. Paired sample t-tests were used to assess changes in caregiver implementation of strategies over time quantified by the MISI-C domain and total scores. Correlations between changes in caregiver strategies (MISI-C) and changes in child social communication (Brief Observation of Social Communication [BOSCC]; Grzadzinski et al., 2016) were observed using Pearson’s r.

Results: EFA results supported a five-factor model (CFI=0.09, RMSEA=0.59) (Table 1). Total score ICCs for IRR and TRT reliability were 0.80 and 0.92, respectively. Significant changes over time were observed for all five domains and total MISI-C scores (p<0.01), with medium to large effect sizes ranging from 0.5-0.9 (Figure 1). Statistically significant associations between changes in caregivers’ implementation of interactive strategies (MISI-C) and changes in children’s social communication (BOSCC) were found ranging from r= -.33 to -.49 (p<.05).

Conclusions: Results show promising, initial evidence for strong reliability and validity of the MISI-C as an outcome measure that captures changes in caregiver implementation of interactive strategies. Additionally, changes in caregivers’ implementation of strategies were significantly associated with changes in children’s social communication over the course of varying treatment models. This novel outcome measure could allow a uniform measurement approach to assessing treatment effects on caregivers, and thus enabling replications and the aggregation of samples across different intervention trials to increase statistical power.