Using an annual over-75 health check to screen for depression: Validation of the short Geriatric Depression Scale (GDS15) within general practice

Objective. To validate the short Geriatric Depression Scale (GDS15) as a sc reening instrument and determine the optimal cutpoint for detecting depress ion among older people living in the community. Design. Two stage study with the first stage consisting of a health check o f people aged 75 years and over by a practice nurse which included the GDS1 5. A second-stage diagnostic interview including the criterion standard was carried out blind to GDS15 score. Setting. A large general practice in Melton Mowbray, Leicestershire, UK. Patients. A random sample (stratified according to first-stage GDS15 score) of 257 older people living in the community, without significant cognitive impairment, were selected for the second-stage diagnostic interview. Measures. The first-stage GDS15 score was compared with diagnostic status f or depression and anxiety disorders (according to ICD-10 criteria) and pres ence of depressive symptoms at the second-stage clinical interview. Results. Ninety-three per cent of those eligible for the study were success fully screened with the GDS15. A cutpoint of < 3/3+ had a sensitivity of 10 0% and specificity of 72% in detecting cases of depression but fewer than o ne in five of those testing positive reached a diagnostic threshold. Only 2 5% of those with a diagnosis of depression had any mention of mental health problems in their medical notes in the year prior to the clinical intervie w. For detecting depressive symptoms the same cutpoint was 79% sensitive an d 78% specific with a positive predictive value of 46%. Conclusions. Used as part of an annual over-75 health check in primary care , the GDS15 would detect a significant amount of hidden morbidity which wou ld serve the original purpose of the annual elderly health checks in the UK . Copyright (C) 1999 John Wiley & Sons, Ltd.