A validation study of the Clinician's Tardive Inventory (CTI)

Abstract

Current clinician-rated tardive dyskinesia (TD) symptom scales do not address expanding clinical signs and functional impacts. The Clinician's Tardive Inventory (CTI) is a newly developed instrument documenting designed by movement disorder specialists and psychiatrists. It is comprised of 6 anatomic domains generating a combined movement amplitude/frequency severity score (CSS), and a functional sore. This study tested the validity of the CTI.

Methods: Videotaped patient assessments and vignettes were rated with the CTI and Abnormal Involuntary Movement Scale (AIMS) administered on the same patient. Construct validity was determined by agreement between the CTI CSS and AIMS dyskinesia score via a Spearman rho. Exploratory analyses examined correlations between the CTI Functional Score, AIMS functional questions 9 and 10, and the CTI CSS. We examined the AIMS dyskinesia score versus AIMS questions 9 and 10.

Results: Seventy patients were assessed. Mean (SD) age: 59 (12) years; 51 % (73 %) were female. CSS and AIMS dyskinesia scores were highly correlated: .770 (95 % CI .653, .851). CTI Functional Score was also highly correlated with the AIMS functional questions 9: .626 (95 % CI .458, .750) and question 10: .771 (95 % CI .655, .852). CSS was not well correlated with the CTI Functional score: .285 (95 % CI .0536, .487). AIMS dyskinesia score was also weakly correlated with questions 9: .299 (95 % CI .069, .499), and 10: .395 (95 % CI .176, .576.).

Conclusions: CTI incorporates updated understanding of phenomenology and demonstrates validity in assessing TD movement severity. Consistent with clinical experience, movement severity does not correlate with functional impacts.