Feasibility of a self-report interview of mental functions in the International Classification of Functioning, Disability and Health (ICF): Cognitive interviewing with persons with work disabilities due to psychiatric conditions

The Mental Functions chapter of the International Classification of Functioning, Disability and Health (ICF) contains a number of items that include cognitive, emotional, and interpersonal functions as well as symptoms that have been found to be related to vocational outcome for people with psychiatric disabilities, but is not designed as a stand-alone assessment instrument. For this study, sixteen research participants were recruited to conduct cognitive testing of a self-report version of the Mental Functions Chapter of the ICF Checklist. Respondents were interviewed in person using a semi-structured cognitive interview protocol about their understanding of interview questions, item definitions, and process of responding to questions. Data were qualitatively analyzed using a content analysis approach to identify problematic questions and to suggest modifications. Cognitive testing improved the questions about Mental Functions so that most items were easily understood by people with psychiatric disabilities. Many complex cognitive functions were not directly relevant to work or were difficult to understand even with significant revision and were deleted. Higher-level mental functions also were deleted, as they were not useful as screening items for proceeding with the detailed third and fourth level sub-items. The questions easiest to understand were physiological functions (e.g., energy and drive), emotional functions (e.g., range of emotion), and some specific cognitive functions (e.g., sustaining attention). All questions required at least minor changes and more than half of the items were deleted due to problems in comprehension, decision process, or response process. Ratings of problems in Mental Functions using the Impairment Rating Scale reflected the personal experiences of respondents and not standard behavioral anchors. The resulting survey contained 52 questions, reduced from 127 items in the original mental functions chapter that people with psychiatric disabilities could consistently understand to report problems in cognitive and emotional functions in work situations. Further refinement and testing of the ICF Impairment Rating Scale is recommended to improve consistency in responses. Social and interpersonal items are missing from the ICF Mental Functions chapter, and are important types of questions to add to future surveys.