Psychometric Properties of the Geriatric Anxiety Scale in Community-Dwelling, Clinical, and Medical Samples of Older Adults

This study examined the psychometric properties of the Geriatric Anxiety Scale (GAS; Segal, June, Payne, Coolidge, & Yochim, 2010) in three samples of older adults using both classical test theory (CTT) and item response theory (IRT) techniques. Study One was conducted in a community-dwelling sample of older adults. Factor analysis revealed that a one- or two- factor solution best fit the data. The GAS also had excellent reliability and adequate convergent validity with other measures, though it lacked discriminant validity with a measure of depression. Study Two examined the psychometric properties in a clinical sample of older adults, and the GAS performed largely similar in this population. Study Three utilized a medical sample of older individuals, and found that the GAS had moderate relationships to self-reported subjective health status. Study Four used IRT to examine the item properties of the scale in all three samples, and a short form (GAS-10) was also created. Two items were flagged for differential item functioning (DIF), but the degree of DIF was negligible. Women scored significantly higher than men on the GAS and subscales, and adults younger than 80 scored significantly higher on the Cognitive subscale than adults 80 and up. Results from the studies indicated that the GAS has strong psychometric properties. Implications and future directions of study are discussed.