Studies on Quality of Life : A Methodological Perspective on the Definition and Measurement of the Good Life in Patients with Psychiatric Illness

Abstract: Background: In social sciences the quality of life (QOL) concept is often connected with efforts to evaluate welfare and well being. In medicine QOL is frequently used as a complement to evaluations of cure. In psychiatry QOL is of special importance because many patients have to endure long periods of illness.Aims: The thesis proposes a definition and operationalization of the QOL concept from a psychiatric perspective, bearing in mind that groups of patients may have a reduced ability to make proper self-observations.Results: The proposed method measures QOL by means of 17 external, interpersonal and internal variables, contrasting the patients own view (the subjective scale) with that of an interviewer’s view based on rating instructions in a manual (the interviewer scale). Reliabilities and feasibility were shown to be good for the interviewer scale and acceptable for the subjective scale, if respondents have an intact self-observing capacity.The results from the empirical studies concerning levels of QOL for five groups of respondents indicate that the interviewer scale differentiates significantly between healthy respondents as well as patients with varying degrees of illness, suggesting that this scale is sensitive to background differences between respondents. The subjective scale did not discriminate between different psychiatric groups. Both scales had acceptable internal consistencies. Variables in the interviewer scale proved to be sensitive to background differences in treatments, diagnosis, varying symptoms and degrees of psychosocial stress. Cluster analyses of variables resulted in re-appearing core clusters in different samples, indicating that respondents ‘Self-image’, ‘Happiness’, ‘Freedom’, and ‘Security’ are central in the proposed QOL concept. These results were consistent between both scales.Conclusions: The interviewer scale based on the existence of general life values proved to be reliable, valid and acceptable. The subjective scale proved to be a complement to the interviewer scale, reliable and feasible for respondents with intact self-observing capacities. The scales appear to differ in focus by giving more emphasis either on general life values (the interviewer scale) or on people’s adjustment to various life situations (the subjective scale).