Background: Anxiety symptoms and anxiety disorders are highly prevalent among elderly people, although infrequently the subject of systematic research in this age group. One important limitation is the lack of a widely accepted instrument to measure dimensional anxiety in both normal old people and old people with mental health problems seen in various settings. Accordingly, we developed and tested of a short scale to measure anxiety in older people.
Methods: We generated a large number of potential items de novo and by reference to existing anxiety scales, and then reduced the number of items to 60 through consultation with a reference group consisting of psychologists, psychiatrists and normal elderly people. We then tested the psychometric properties of these 60 items in 452 normal old people and 46 patients attending a psychogeriatric service. We were able to reduce the number of items to 20. We chose a 1-week perspective and a dichotomous response scale.
Results: Cronbach's alpha for the 20-item Geriatric Anxiety Inventory (GAI) was 0.91 among normal elderly people and 0.93 in the psychogeriatric sample. Concurrent validity with a variety of other measures was demonstrated in both the normal sample and the psychogeriatric sample. Inter-rater and test-retest reliability were found to be excellent. Receiver operating characteristic analysis indicated a cut-point of 10/11 for the detection of DSM-IV Generalized Anxiety Disorder (GAD) in the psychogeriatric sample, with 83% of patients correctly classified with a specificity of 84% and a sensitivity of 75%.
Conclusions: The GAI is a new 20-item self-report or nurse-administered scale that measures dimensional anxiety in elderly people. It has sound psychometric properties. Initial clinical testing indicates that it is able to discriminate between those with and without any anxiety disorder and between those with and without DSM-IV GAD.