Usefulness of two instruments in assessing depression among elderly Mexicans in population studies and for primary care.
OBJECTIVE
To determine the psychometric qualities of the CES-DR and GDS scales in the elderly and compare them to clinical psychiatric diagnoses.


MATERIAL AND METHODS
The first phase consisted of home interviews for determining the psychometric qualities of the GDS and CES-DR scales. In the second phase, psychiatrists conducted diagnostic interviews. The sample consisted of 534 participants older than 60 years of age insured by the Mexican Institute of Social Security.


RESULTS
First phase: Cronbach's alpha for the GDS was 0.87 and 0.86 for CES-DR. The GDS factorial analysis found eight factors that could explain 53.5% of the total variance and nine factors that explained 57.9% in the CES-DR. Second phase: Compared to the psychiatric diagnoses, CES-DR reported a sensitivity of 82% and a specificity of 49.2%; GDS reported 53.8% sensitivity and 78.9% specificity.


CONCLUSIONS
CES-DR and GDS scales have high reliability and adequate validity but the CES-DR reports higher sensitivity.