Development and reliability of a structured interview guide for the Montgomery Asberg Depression Rating Scale (SIGMA).

BACKGROUND The Montgomery-Asberg Depression Rating Scale (MADRS) is often used in clinical trials to select patients and to assess treatment efficacy. The scale was originally published without suggested questions for clinicians to use in gathering the information necessary to rate the items. Structured and semi-structured interview guides have been found to improve reliability with other scales. AIMS To describe the development and test-retest reliability of a structured interview guide for the MADRS (SIGMA). METHOD A total of 162 test-retest interviews were conducted by 81 rater pairs. Each patient was interviewed twice, once by each rater conducting an independent interview. RESULTS The intraclass correlation for total score between raters using the SIGMA was r=0.93, P<0.0001. All ten items had good to excellent interrater reliability. CONCLUSIONS Use of the SIGMA can result in high reliability of MADRS scores in evaluating patients with depression.