Measuring social isolation in older adults: Development and initial validation of the friendship scale

Although there are many excellent published scales measuring social isolation, there is need for a short, user-friendly, stand alone scale measuring felt social isolation with good psychometric properties. This study reports the development and preliminary validation of a short, user-friendly scale, the Friendship Scale. The six items measure six of the seven important dimensions that contribute to social isolation and its opposite, social connection. The psychometric properties suggest that it has excellent internal structures as assessed by structural equation modelling (CFI = 0.99, RMSEA = 0.02), that it possesses reliability (Cronbach alpha = 0.83) and discrimination when assessed against two other short social relationship scales. Tests of concurrent discriminant validity suggest it is sensitive to the known correlates of social isolation. Although further work is needed to validate it in other populations, the results of this study suggest researchers may find the Friendship Scale particularly useful in epidemiology, population surveys or in health-related quality of life evaluation studies where a parsimonious measure of felt social support or social isolation is needed.