The Tardive Dyskinesia Impact Scale (TDIS) is a patient-reported outcome tool designed to assess how tardive dyskinesia (TD) affects patients’ daily lives—including physical function, emotional well-being, and social interaction. Unlike the commonly used Abnormal Involuntary Movement Scale, which is clinician-reported and focused on the severity of observed movements, the TDIS captures the subjective experience of living with TD. Developed through extensive qualitative research with patients and caregivers, and refined based on feedback, the 11-item questionnaire asks patients to rate how uncontrollable movements impact speech, mobility, dexterity, pain, social encounters, and emotional health. Findings from two phase 3 clinical trials (KINECT3 and KINECT4) confirmed that the TDIS is reliable, valid, and responsive to changes in symptom burden over time.

Psychometric analyses revealed that the TDIS has two core domains—physical and socioemotional impacts—with strong internal consistency and test–retest reliability. The scale was able to detect symptom improvement during treatment and worsening during medication washout, indicating its usefulness as a monitoring tool in both clinical trials and real-world care. Importantly, TDIS scores had weak correlation with AIMS, highlighting that the two tools measure different aspects of TD and should be used together for a more complete picture. The TDIS fulfills FDA recommendations for incorporating the patient voice into clinical assessments and offers a practical, validated solution for tracking how TD affects quality of life from the patient’s point of view.

Reference: Farber RH, Stull DE, Witherspoon B, et al. The Tardive Dyskinesia Impact Scale (TDIS), a novel patient-reported outcome measure in tardive dyskinesia: development and psychometric validation. J Patient Rep Outcomes. 2024;8(1):2. doi: 10.1186/s41687-023-00679-4.