RELIABILITY AND VALIDITY OF A TARDIVE-DYSKINESIA VIDEOTAPE RATING TECHNIQUE

Psychiatric inpatients (94) receiving regular antipsychotic medication, were videotaped using a standard procedure. The tapes were rated by blind observes using a simple scoring system for the duration of abnormal movements. Using this combined videotape and rating scale assessment technique the re-rating reliability, inter-rater reliability and test-retest reliability were high. To demonstrate the validity of the technique the rating scale scores in a sub-sample of 30 patients, were compared with the assessment of 3 experienced clinicians on the same patients and AIMS [Abnormal Involuntary Movements Scale] scores. Central (lip, tongue, jaw and neck movements) scores showed close agreement with the clinicians'' assessment, suggesting that clinical diagnosis is based principally on the presence and severity of oro-facial dyskinesia. Total rating scale scores were in close accord with total AIMS scores. When the 2 scales were carried out on the same patients on the same occasion a diagnostic criterion level of 2 or more on the central score produced a tardive dyskinesia prevalence rate identical to that produced by an AIMS criterion level of 2 or more on the global severity rating. The tardive dyskinesia prevalence rate based on the central score criterion level showed an increase with age.