Rasch analysis of the illness management and recovery scale-clinician version

Abstract

Rationale, aims and objectives The illness management and recovery scale-clinician version (IMRS-C) is a measure of outcomes thought to be important indicators of progress for consumers participating in illness management and recovery (IMR). Prior research has examined the psychometric properties of the IMRS-C; extant research supports certain aspects of the scale's reliability (test–retest) and validity (sensitivity to interventions). Analyses based on Rasch provide certain advantages and have not been applied to the IMRS-C.

Method This study used an archival IMRS database including responses regarding 697 participants with severe mental illness from a variety of community-based settings. Rasch analyses were utilized to determine item functioning and utility of the IMRS-C.

Results Results of Rasch analyses using the IMRS-C as one unidimensional scale were problematic. Analyses grouping items into three separate scales measuring recovery, management and biological vulnerability were more promising, but the third scale had other limitations.

Conclusions Results suggest that the items included in the IMRS-C can form two screeners, one for recovery and one for management; items regarding biological vulnerability were inadequate. The assessment could be supplemented by more refined measures of coping/self-management and recovery constructs.