Development of a Rasch-Calibrated Test for Assessing Implied Meaning in Patients With Schizophrenia

Importance: Patients with schizophrenia tend to have severe deficits in theory of mind, which may limit their interpretation of others' behaviors and thereby hamper social participation. Commonly used measures of theory of mind assess the ability to understand various social situations (e.g., implied meaning or hinting, faux pas), but these measures do not yield valid, reliable, and gender unbiased results to inform interventions for managing theory-of-mind deficits. We used understanding of implied meaning, which appears to be a unidimensional construct highly correlated with social competence, as a promising starting point to develop a theory-of-mind assessment. Objective: To develop a Rasch-calibrated computerized test of implied meaning. Design: Cross-sectional design. Setting: Psychiatric hospitals and community. Participants: 344 participants (240 patients with schizophrenia and 104 healthy adults). Results: We initially developed 27 items for the Computerized Implied Meaning Test. After inappropriate items (12 misfit items and 1 gender-biased item) were removed, the remaining 14 items showed acceptable model fit to the Rasch model (infit = 0.84-1.16; outfit = 0.65-1.34) and the one-factor model (comparative fit index 5.91, standardized root mean square residual 5.05, root-mean-square error of approximation 5.08). Most patients (81.7%) achieved individual Rasch reliability of >=.90. Healthy participants performed significantly better on the test than patients with schizophrenia (Cohen's d = 2.5, p < .001). Conclusions and Relevance: Our preliminary findings suggest that the Computerized Implied Meaning Test may provide reliable, valid, and gender-unbiased results for patients with schizophrenia. What This Article Adds: We developed a new measure for assessing theory-of-mind ability in patients with schizophrenia that consists of items targeting the understanding of implied meaning. Preliminary findings suggest that the Computerized Implied Meaning Test is reliable, valid, and gender unbiased and may be used in evaluating patients' theory-of-mind deficits and relevant factors.

Automated summary

This study developed a new measure for assessing theory-of-mind ability in patients with schizophrenia. The Computerized Implied Meaning Test targets the understanding of implied meaning and shows reliable, valid, and gender unbiased results. It can be used to evaluate patients' theory-of-mind deficits and relevant factors.