Objective: To study the interrater reliability of a Danish version of the Morgan Russell scale for assessment of patients with anorexia nervosa, and subsequently to clarify the existing rating instructions.
Method: Ten patients undergoing treatment for anorexia nervosa at a regional center participated and had their interview videotaped. Two interviews were reserved for a training phase only. The group of raters comprised eight clinicians, and measures of interrater reliability were computed using intraclass correlation coefficient (ICC).
Results: The ICC for the total score was good (0.79), while reliability for the single items varied from poor to excellent (0.14-0.99). Internal consistency as expressed by Cronbach's coefficient alpha was acceptable (0.74).
Discussion: The Morgan Russell scale stands out as an easily applied and reliable measure of severity of anorexia nervosa, though the rating instructions need clarification in some items.