Comparison of short scales to measure depressive symptoms in elders with diabetes

Depression is the most common mental health problem among American elders and it is also prevalent among those with diabetes. The 20-item Center for Epidemiological Studies Depression Scale (CES-D) is commonly used to measure depressive symptoms in elders, but its length is potentially burdensome. Twelve short forms of the CES-D (4 to 16 items) exist, but they have not been tested with elders with diabetes. This study compared reliability and validity estimates across the 12 short forms and investigated similarities in classifying elders with diabetes as clinically depressed using standardized cut scores. Beck's theory provides a framework for identifying the affective, cognitive, behavioral, and somatic symptoms that are measured by the CES-D. Data were merged from two studies, which yielded 80 elders with diabetes who completed the CES-D items during structured interviews. Cronbach's alpha was .87 for the CES-D; it ranged from .60 (5 items) to .84 (16 items) for shorter forms. Correlations of the full CES-D and short forms ranged from .82 (4 items) to .98 (16 items). Using the CES-D cut score, 14% of the elders with diabetes had clinically significant depressive symptoms: 21% men, 11% women, 17% African Americans, and 13% Caucasians. A 5-item scale overestimated 29% as clinically depressed: 33% men, 27% women, 25% African Americans, and 29% Caucasians. The findings suggest that shortened scales to measure depressive symptoms may be potentially useful with elders with diabetes. Further psychometric studies of the CES-D short forms are recommended with elders with chronic conditions.