Tardive Dyskinesia Impact Scale Captures Relevant Info About Condition

Patient-reported outcome measure captures unique content compared with clinician-reported outcome measure AIMS

By Elana Gotkine HealthDay Reporter

FRIDAY, Jan. 19, 2024 (HealthDay News) — The Tardive Dyskinesia Impact Scale (TDIS) patient-reported outcome measure captures information about the impact of TD, according to a study published online Jan. 4 in the Journal of Patient-Reported Outcomes.

Robert H. Farber, Ph.D., from Neurocrine Biosciences Inc. in San Diego, and colleagues used data from qualitative studies and phase 3 trials of a VMAT2 inhibitor for treatment of TD to determine the psychometric properties of the TDIS. To assess how well the TDIS captured key domains of TD impact, qualitative research included concept elicitation and cognitive debriefing interviews with TD patients and their caregivers. The psychometric properties of the TDIS were examined with quantitative analysis including assessing construct validity and responsiveness to change.

The researchers found that the key TD impacts reported by patients and caregivers were captured by the TDIS; the TDIS was interpreted as intended and relevant to patients’ experiences based on qualitative results. Evidence of two underlying domains of the TDIS was found in quantitative results: physical and socioemotional. Compared with the clinician-rated outcome (Abnormal Involuntary Movement Scale), the TDIS captured unique content based on known groups and predictive validity. Responsiveness to change in treatment was seen with the TDIS, with improvement noted in TDIS scores over 48 weeks in two phase 3 trials.

“The TDIS can be easily administered in a clinician’s office or at a patient’s home to provide insight about TD impact and whether the impact is lessening or increasing,” the authors write.

Several authors disclosed ties to biopharmaceutical companies, including Neurocrine Biosciences, which funded the study.