Objective: To develop and validate a Spanish version of the Geriatric Depression Scale (GDS) for telephone administration.
Design, setting, and patients: The original version of the GDS was translated into Spanish. A random sample of 282 ambulatory elderly individuals was contacted by phone. Those completing the phone GDS (GDS-T) were asked to schedule an appointment within two weeks in which we collected data on demographics, physical exam, functional and mental status, and a face-to-face version of the GDS (GDS-P). We estimated question-to-question kappa statistics and the Pearson correlation coefficient between the GDS-T and GDS-P scores. We evaluated reliability of the GDS-T and GDS-P using the Cronbach's alpha coefficient. We estimated the sensitivity, specificity, and criterion validity of the GDS using the DSM IV criteria for depression as our gold standard.
Results: Thirty patients (11%) refused to participate. Of the remaining 252 patients, 169 (67%) attended the personal interview. The Cronbach's alpha coefficient was 0.85 for GSD-P and 0.88 for GDS-T. Sensitivity and specificity were 88% and 82% for GDS-P and 84% and 79% for GDS-T. The prevalence of depression in the group completing both scales was 12.8% using the GDS-P and 14.9% using the GDS-T (P >.05). Among those who only completed the GDS-T, the prevalence was 22.7% (P <.05) suggesting that depressed patients kept their appointments less frequently.
Conclusions: The telephone GDS had high internal consistency and was highly correlated with the validated personal administration of the scale, suggesting that it could be a valid instrument for screening of depression among elderly ambulatory Spanish-speaking patients. Because the depression rate was significantly higher among those not presenting to the personal evaluation, the adoption of GDS-T may help detect and plan early interventions in patients who otherwise would not be identified.