Adaptation into Spanish of the Clinically Useful Depression Outcome Scale (CUDOS) for assessing major depressive disorder from the patient's perspective.

OBJECTIVE To adapt the CUDOS scale (Clinically Useful Depression Outcome Scale) into Spanish and to test its psychometrical properties in a sample of patients with major depressive disorder (MDD). METHODS A two-step cross-sectional, multicenter validation study was conducted (linguistic adaptation into Spanish and psychometric validation). The study evaluated patients attended in Primary Care with a MDD diagnosis within the last 3 months (DSM-IV TR criteria). The following scales were administered: CUDOS, PRIME-MD (Primary Care Evaluation of Mental Disorders), HAMD-17 (Hamilton Depression Rating Scale), SOFAS (Social and Occupational Functioning Assessment Scale), SF-36 (Physical –PCS- and Mental –MCS- Component Summaries), and the CGI-S & PGI-S (Clinical Global Impression for Severity of Illness scales for clinicians and patients, respectively). Feasibility, reliability, and validity of the Spanish version were assessed. RESULTS In the validation study, 305 MDD patients (69.5% female) with a mean age (standard deviation-SD-) of 51.75(15.53) were included. Mean completion time was 4.47(2.4) minutes. Floor or ceiling effects were found in less than 1% of the case scores. Internal consistency was adequate (Cronbach's α= 0.88). Pearson correlation coefficients with CUDOS were: -0.42 (SOFAS), 0.45 (HAMD-17), -0.22 (PCS), -0.65 (MCS); all p<0.001. The CUDOS properly discriminated among clinical severity levels (p<0.03). CONCLUSIONS The adapted Spanish version of the CUDOS shows adequate psychometric properties as an evaluation instrument of major depression from the patient's perspective.