[Quality of life. Construct validation and the development of a modular system]

Abstract

The construct Quality of Life (QoL) is investigated by metaanalysis of eight (inter)nationally validated questionnaires in a multicenter study. Data have been collected in a mentally healthy (n = 479), a depressed (n = 171) and a schizophrenic (n = 139) sample. Conventional psychometric criteria and a facet analytical methodology have been applied. The resulting questionnaire "Modular System for Quality of Life" (MSQoL) consists of a core module with 47 items (one "G-factor" and six subdimensions), which is sufficiently valid for all three samples. Additionally, there are four specific modules (demography, family, partnership, profession). No specific modules can be identified for the psychopathological subgroups. The validated radex structure for subjective QoL offers the opportunity for a cumulative research design and for adaptations to the actual setting.