Factor analysis of the Mayo-Portland Adaptability Inventory: Structure and validity

Abstract

Principal components (PC) factor analysis of the Mayo Portland Adaptability Inventory (MPAI) was conducted using a sample of outpatients (n=189) with acquired brain injury (ABI) to evaluate whether outcome after ABI is multifactorial or unifactorial in nature. An eight factor model was derived which explained 64.4% of the total variance. The eight factors were interpreted as representing Activities of Daily Living, Social Initiation, Cognition, Impaired Self awareness Distress, Social Skills Support, Independence, Visuoperceptual, and Psychiatric, respectively. Validation of the Cognition factor was supported when factor scores were correlated with various neuropsychological measures. In addition, 117 patient self rating total scores were used to evaluate the Impaired Self awareness Distress factor. An inverse relationship was observed, supporting this factor's ability to capture the two dimensional phenomena of diminished self awareness or enhanced emotional distress. A new subscale structure is suggested, that may allow greater clinical utility in understanding how ABI manifests in patients, and may provide clinicians with a better structure for implementing treatment strategies to address specific areas of impairment and disability for specific patients. Additionally, more precise measurement of treatment outcomes may be afforded by this reorganization.