The clinical relevance of changes in the Montgomery-Asberg Depression Rating Scale using the minimum clinically important difference approach.
OBJECTIVE
To identify the minimal clinically important difference (MCID) for the Montgomery-Asberg Depression Rating Scale (MADRS) in randomised studies of depression, and to cross-validate the estimated MCID.


METHODS
Placebo-treated patients from three similarly-designed, 8-week, double-blind, randomised depression trials with a stable health status between baseline and Week 1 ('no change' rating on the Clinical Global Impression-Improvement scale) were eligible. To calculate the MCID using the distribution-based approach, the standard deviation was estimated using baseline MADRS data while the reliability parameter was measured as the intraclass correlation coefficient between baseline and Week 1. For cross-validation, patients from an observational study were matched to identify the 'MCID change' (MADRS change from baseline to endpoint score plus the estimated MCID) and 'control' groups. Comparisons of clinical and health-related quality of life measures were performed.


RESULTS
In total, 177 placebo-treated patients were identified. MCID estimates for MADRS ranged from 1.6 to 1.9. A total of 105 matched pairs were identified for the cross-validation analyses. Mean change from baseline in MADRS scores (10.6 +/- 8.5 vs. 12.5 +/- 7.9, p = 0.038) and remission rates (71.6% vs. 57.1%, p < 0.05) significantly differed between the 'MCID change' and 'control' groups at endpoint. Numerically higher response rates and greater improvements in HRQoL scores in the 'MCID change' group were also found.


CONCLUSIONS
These preliminary findings support the value of the estimated MCID for the MADRS and may aid decision makers in evaluating antidepressant treatment effects and improving long-term patient outcomes.
Duru
Gérard
G
CNRS (French National Center for Scientific Research), Université Claude Bernard Lyon I, France. gduru@univ-lyon1.fr
Fantino
Bruno
B
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D015283:Citalopram / Q000008:administration & dosage* / Q000009:adverse effects; D003430:Cross-Sectional Studies; D003865:Major Depressive Disorder / Q000175:diagnosis* / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D011336:Probability; D011569:Psychiatric Status Rating Scales; D011788:Quality of Life; D016032:Randomized Controlled Trials as Topic; D018570:Risk Assessment; D012720:Severity of Illness Index; D012737:Sex Factors; D016896:Treatment Outcome; D054928:Validation Studies as Topic
D015283:Citalopram