Quality of Life in Epilepsy: Multidimensional Profile and Underlying Latent Dimensions

Abstract

Part of our study, the Dutch Quality of Life and Quality of Care Investigation in Epilepsy (DUQQIE), intended to cover several of the components of the quality of life (QoL) concept. To this end, a series of already existing generic and disease-specific instruments was selected covering several parts of the QoL components in order to construct a multidimensional “QoL profile” for people with epilepsy and to look for underlying second-order QoL dimensions. From the records of four outpatient clinics, 210 persons with epilepsy were randomly selected. During their visit to the outpatient clinic, they completed a questionnaire assessing, among others, health perceptions, psychological well-being, and social functioning. Additional information about their medical and psycho–social status was gathered from the patient files. A large part of our research group was not seizure-free. As far as comparisons with other patient or healthy groups could be made, it appeared that they mostly did not (much) worse and all scores were above the scale midpoint. However, almost two-thirds of the scale means lied below a so-called “normative mean.” Higher-order factor analysis yielded one general factor measuring the “Overall Quality of Life.” Furthermore, after rotation of this general factor, two separate factors could be constructed referring to the psycho–physical and psycho–social aspects of QoL, respectively. We decided not to develop “quality of life instrument” de novo to the already vast and ever increasing area of QoL instruments, but to use already existing, mostly generic, and well-validated instruments. The most important advantage of this approach is that it allows for “normative controls” (norms; other groups) and “conceptual modeling.” The latter is that the QoL concept can be unfolded into its component parts and hypothetically related to each other.