Screening performance of the 15-item geriatric depression scale in a diverse elderly home care population.
OBJECTIVE
To empirically evaluate the psychometric properties of the 15-item Geriatric Depression Scale (GDS-15); determine the optimal cutoff points and screening performance for the detection of major depression; and examine differential item functioning (DIF) to determine the variability of item responses across sociodemographics in an elderly home care population.


METHODS
A secondary analysis of data collected from a random sample study.


METHODS
Homebound subjects newly admitted over a 2-year-period to a large visiting nurse service agency in Westchester, New York.


METHODS
Five hundred twenty-six subjects over age 65, newly admitted to home care for skilled nursing.


METHODS
Major depression was diagnosed using both patient, Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, and best estimate procedures. Self-report measures included the GDS-15, activities of daily living (ADL), instrumental ADL, and pain intensity. Cognitive impairment was assessed using the Mini-Mental State Examination and medical morbidity using the Charlson Comorbidity Index.


RESULTS
Optimal cutoff (5) yielded sensitivity 71.8% and specificity of 78.2%, however, the accuracy of the GDS-15 was not influenced by severity of medical burden. Persons with a cluster of ailments were twice as likely (Adj odds ratio = 2.47; 95% confidence interval = 1.49-4.09) to be diagnosed with depression. DIF analyses revealed no variability of item responses across sociodemographics.


CONCLUSIONS
Main findings suggest that the accuracy of the GDS-15 was not influenced by severity of clinical or functional factors, or sociodemographics. This has broad implications suggesting that the very old, ill, and diverse populations can be appropriately screened for depression using the GDS-15.
Marc
Linda G
LG
Department of Psychiatry, Weill Medical College of Cornell University, Westchester, NY, USA. linda.marc@post.harvard.edu
Raue
Patrick J
PJ
Bruce
Martha L
ML
D000203:Activities of Daily Living / Q000523:psychology; D000368:Aged; D000369:Aged, 80 and over; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology; D003865:Major Depressive Disorder / Q000175:diagnosis* / Q000453:epidemiology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D015577:Geriatric Assessment / Q000379:methods; D006699:Home Care Services; D018577:Homebound Persons; D006801:Humans; D007406:Interview, Psychological / Q000379:methods*; D016015:Logistic Models; D008297:Male; D008403:Mass Screening / Q000379:methods*; D009483:Neuropsychological Tests; D009518:New York / Q000453:epidemiology; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires