Young Mania Rating Scale: how to interpret the numbers? Determination of a severity threshold and of the minimal clinically significant difference in the EMBLEM cohort

EMBLEM Study Grp, Jim van Os

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

The aim of this analysis was to identify Young Mania Rating Scale (YMRS) meaningful benchmarks for clinicians (severity threshold, minimal clinically significant difference [MCSD]) using the Clinical Global Impressions Bipolar (CGI-BP) mania scale, to provide a clinical perspective to randomized clinical trials (RCTs) results. We used the cohort of patients with acute manic/mixed state of bipolar disorders (N?=?3459) included in the European Mania in Bipolar Longitudinal Evaluation of Medication (EMBLEM) study. A receiver-operating characteristic analysis was performed on randomly selected patients to determine the YMRS optimal severity threshold with CGI-BP mania score?"Markedly ill" defining severity. The MCSD (clinically meaningful change in score relative to one point difference in CGI-BP mania for outcome measures) of YMRS, was assessed with a linear regression on baseline data. At baseline, YMRS mean score was 26.4 (?9.9), CGI-BP mania mean score was 4.8 (?1.0) and 61.7% of patients had a score?5. The optimal YMRS severity threshold of 25 (positive predictive value [PPV]?=?83.0%; negative predictive value [NPV]?=?66.0%) was determined. In this cohort, a YMRS score of 20 (typical cutoff for RCTs inclusion criteria) corresponds to a PPV of 74.6% and to a NPV of 77.6%, meaning that the majority of patients included would be classified as severely ill. The YMRS minimal clinically significant difference was 6.6 points.
Original languageEnglish
Pages (from-to)46-58
JournalInternational Journal of Methods in Psychiatric Research
Volume22
Issue number1
DOIs
Publication statusPublished - Mar 2013

Keywords

  • bipolar disorder
  • severity threshold
  • Young Mania Rating Scale
  • receiver-operating characteristic analysis
  • minimal clinically significant difference

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