Development of a New Self-Rating Tool for Assessing Work Capability in Individuals with Mental Disorders and/or Intellectual Disabilities: The Revised Mini-ICF-App-S (RMIAS) and its Psychometric Properties

Background There is a growing need for a self-assessment tool to evaluate work capacity that can be used by people with a range of disabilities, including those with cognitive and language impairments. Objective This study aimed to create and test a new self-rating scale, the RMIAS, for assessing work capacity in Japanese. The RMIAS is an updated version of the Mini-ICF-APP-S, designed to be suitable not only for individuals with mental disabilities but also for those with mild intellectual disabilities. Methods We conducted two surveys – one with 155 users of a disability employment support center and another with 145 people from the general adult population. The Mini-ICF-APP-S was revised to ensure that people with mild cognitive or language impairments could understand and respond to the questions effectively. Resutls Responses to the questions were well-distributed. Factor analyses showed that the RMIAS measures almost the same concepts as the Mini-ICF-APP-S. The test-retest reliability over 1–5 weeks was moderate and the RMIAS subscale scores were correlated with those of WHO-DAS 2 as expected. Conclusion We successfully developed the RMIAS, a revised version of the Mini-ICF-App-S, and demonstrated its reliability and validity.