Objective: To standardize the EURO-D scale as a method for detecting depression in Spanish older people.
Methods: In a first phase, a sample of 1080 community older people was assessed with the GMS-AGECAT by lay interviewers. In a second phase, all the probable cases and a similar number of randomly selected probable non-cases were assessed using DSM-III-R diagnosis by psychiatrists. To test reliability, internal consistency with the Cronbach alpha coefficient and test-retest reliability (Kappa value) were obtained. Validity, sensitivity and specificity, predictive values, Receiver Operating Characteristic (ROC) curve, and Specific Likelihood Ratios (SSLR) were calculated.
Results: A high internal consistency was obtained in both phases of the study (alpha = 0.75; alpha = 0.79, respectively). Test-retest reliability was acceptable (weighted kappa = 0.60). For the prediction of DSM-III-R diagnosis validity coefficients (cut-off point 3/4) were: sensitivity 91.8%, specificity 76.6% and area under the ROC curve 0.92 [95% Confidence Intervals (0.89-0.95)]. Illiteracy and cognitive difficulties had a small negative effect on the performance of the scale.
Conclusions: The EURO-D scale is a reliable and valid instrument for detecting probable cases of depression in older people in Spain. Illiteracy and cognitive difficulties should be considered when interpreting the results.