Adverse outcomes between VMAT2 and anticholinergics in tardive dyskinesia: A target trial emulation.

According to the International Classification of Functioning, Disability and Health (ICF), functioning and disability are a result of the interaction of an individual’s health condition and contextual factors (environmental and personal factors) []. The ICF classification of disability has shifted from the previous medically focused definition to a biopsychosocial approach []. This complex, dynamic, multidimensional, and contested nature of the concept of disability increases the challenges of disability measurement []. Whilst the ICF framework appreciates the interaction between different factors that affect disability and functioning, its complexity in linking the standard instrument of disability measurement to the ICF model conceptually and operationally makes direct implementation in clinical practice challenging []. A variety of ICF-based measurement tools were therefore derived, attempting to develop a standardised procedure to collect disability and functioning data. The World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) was invented in 2010 [,]. It is a 36-item self-administered tool designed to assess functioning in six life domains. The WHODAS 2.0 acted as a generalised and cross-cultural method to measure individuals’ limitations on different activities and social participation in a way that is independent of medical diagnosis []. It has been used in cross-country research for general populations and those with physical, mental, and neurological conditions [,,]. The 36-item WHODAS 2.0 has been validated with adequate reliability in various groups, including arthritis, stroke, chronic psychotic disorder, depression, and back pain [–]. The WHODAS 2.0 supersedes WHODAS II and shows many advantages for example used across all diseases including mental, neurological and addictive disorders; short, simple and easy to administer; applicable in both clinical and general population settings; producing standardized disability levels and profiles; applicable across cultures, in all adult populations and directly linked at the level of the concepts to ICF []. WHODAS 2.0 has been translated into around 50 languages and dialects and is used in almost 30 areas of research in around 100 countries []. Experts in Taiwan once modified and translated WHODAS 2.0 to an instrument called Functioning Disability Evaluation Scale (FUNDES), which was in Traditional Chinese with an excellent internal consistency (Cronbach’s alpha: 0.9); however, it was not applicable in Hong Kong communities as that version included two new domains which were not shown in the English original version [].