"Real world" functioning in schizophrenia patients and healthy adults: assessing validity of the Multidimensional Scale of Independent Functioning.

As treatment efforts to enhance cognitive abilities in schizophrenia increase, so too does the need for a critical appraisal of instruments that measure functionality and adjustment to community living. The Multidimensional Scale of Independent Functioning (MSIF; Jaeger et al., 2003) is a promising instrument that assesses functionality in relation to different life settings, performance levels, responsibilities and environmental supports. However, its applicability to the schizophrenia population has been questioned because relevant data are scarce. This study provides descriptive and validity-related information by reporting MSIF scores in healthy community-dwelling adults (n=71) and in schizophrenia outpatients (n=156). Results show that healthy adults performed within defined "normal" ranges in most MSIF domains in comparison to schizophrenia patients who showed moderate to severe impairments. Moreover, the MSIF distinguished between the two groups with accuracy rates as high as 98% and effect sizes (standardized mean group difference) above 2.0 in almost all domains. Accordingly, the MSIF is a potentially valuable measure of community independence that can inform treatment initiatives and may be adaptable to the evaluation of functionality changes over time. The unique structure and content of information obtained by the MSIF makes it a candidate for inclusion in studies aimed at developing a new generation of instruments for the assessment of real world functioning in schizophrenia.