Validation of a telephone-administered geriatric depression scale in a hispanic elderly population

To develop and validate a Spanish version of the Geriatric Depression Scale (GDS) for telephone administration.

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.

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.

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.