Rater Training for a Multi-Site, International Clinical Trial:What Mood Symptoms may be most Difficult to Rate?

Aims

Given resource constraints in conducting clinical trials, it is critical that rater training focuses on scale items wherein standardization is most challenging. This analysis examined mood disorder symptom ratings submitted in an online rater training program conducted preparatory to the initiation of a multi-site, international mood disorder treatment trial. Ratings were entered online and analyzed for consistency and variability, and compared to established standards (Gold Consensus Ratings/ GCRs).

Methods

Raters participated in web-based rater training on the Hamilton Depression Rating Scale (HAM-D), Montgomery Asberg Rating Scale (MADRS), and Young Mania Rating Scale (YMRS). Training included integration of didactic materials and videos of two bipolar depressed patients interviewed by two U.S. clinicians. Raters viewed the videos and rated the mood scales. Inter-rater agreement was assessed using Kappa statistics. Ratings between the raters and the GCRs for individual scale items were assessed using McNemar test for paired binomial proportions.

Results

194 raters from 16 countries, 80 sites and speaking 20 different languages participated. Interrater agreement on videos ratings ranged from substantial to moderate (HAM-D, Kappa video A = 0.72, video B = 0.65, p < 0.001), (MADRS, Kappa = 0.65 and 0.47, p < 0.001), (YMRS, Kappa = 0.75, and 0.64, p < 0.001). There was no significant difference on agreement based upon on English proficiency, clinical experience, or by country. Scale items that differed from the GCR on the HAM-D were depressed mood, delayed insomnia, retardation, and anxiety (psychic). Items that differed on the MADRS were apparent sadness, inner tension, concentration difficulties, lassitude and inability to feel. Items that differed on the YMRS were irritability and disruptive behavior.

Conclusions

Identification of specific rating scale items in which rater variability is greatest may facilitate training approaches that target these areas for more efficient training in international clinical trials.