Development of transdisciplinary approach scale for healthcare professionals

Abstract Aim This study developed and validated the Transdisciplinary Approach Scale (TDAS), the first instrument specifically designed to assess transdisciplinary collaboration abilities among mental health professionals. While existing scales measure interprofessional collaboration attitudes or general competencies, none explicitly address transdisciplinary‐specific elements such as role release and shared conceptual frameworks. Methods Following a systematic scale development framework, we conducted a literature review, expert content validation, and psychometric testing. Between October 2019 and March 2021, 117 mental health professionals from 14 professions enrolled in the Psychiatric Staff Education Program for Transdisciplinary Approach (PsySEPTA). Baseline data were collected from 96 participants for scale development. Exploratory factor analysis, internal consistency testing, known‐groups validity assessment, and responsiveness evaluation were performed. Pre‐post data from 53 one‐year course participants were used to assess responsiveness to educational intervention. Results The final 10‐item TDAS had a two‐factor structure explaining 57.1% of variance: Transdisciplinary Collaboration (six items, α = 0.881) and Transdisciplinary Practice (four items, α = 0.765). No significant differences were observed across professional groups or genders. Following PsySEPTA participation, significant improvements occurred in both factors (Cohen's d = 0.64–0.73), demonstrating the scale's sensitivity to educational intervention. Conclusion The TDAS is a psychometrically sound, brief instrument for assessing transdisciplinary collaboration abilities. It captures both collaborative processes and their practical application in patient care, filling an important gap where no validated transdisciplinary assessment previously existed. The scale offers a valuable tool for evaluating team‐based, patient‐centered care initiatives.