Abstract
Health scales or indices are composite tools aiming to measure a variety of clinical conditions, behaviors, attitudes and beliefs that are difficult to be measured quantitatively. During the past years, these tools have been extensively used in cardiovascular disease prevention. The already proposed scales have shown good ability in assessing individual characteristics, but had moderate predictive ability in relation to the development of chronic diseases and various other health outcomes. In this review, methodological issues for the development of health scales are discussed. Specifically, the selection of the appropriate number of components, the selection of classes for each component, the use of weights of scale components and the role of intra- or inter-correlation between components are discussed. Based on the current literature the use of components with large number of classes, as well as the use of specific weights for each scale component and the low-to-moderate inter-correlation rate between the components, is suggested in order to increase the diagnostic accuracy of the tool.