Impact-Tardive Dyskinesia (Impact-TD) Scale

Objective: Tardive dyskinesia (TD) is a movement disorder that can negatively affect health-related quality of life. However, the impact of TD is not necessarily dependent solely on the objective severity of TD movements. There is currently no easy-to-use, standardized, clinician-rated assessment of the impact of TD on functioning. The aim of this consensus panel was to develop a scale (Impact-TD scale) to assess the impact of TD on patients' daily functioning in practice settings.Participants: Nine health care professionals with expertise in TD and clinical scale development met to discuss how TD negatively impacts the functional activities of patients.Evidence: This panel comprised 7 individuals from a previous panel that developed recommendations on the importance of optimally assessing the functional impact of TD. The previous panel published a narrative literature review that summarized the existing approaches to assess the impact of TD in clinical research and practice.Consensus Process: A modified Delphi process was used to assess agreement on the format and content of the Impact-TD scale. The panel discussed key features of the Impact-TD scale (ie, simplicity, usability, assessment of frequency of impact versus interference/distress). The scale aimed to describe specific consequences of TD symptoms with which patients may have difficulty.Conclusions: Consensus was reached on a list of consequences of TD symptoms that have a functional impact and were categorized in 4 functional domains: social, psychological/psychiatric, physical, and vocational/educational/recreational. The Impact-TD scale offers an easy-to-use clinical scale to measure the functional impact of TD in practice settings.