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.