Comparison of two instruments for measurement of quality of life in clinical practice - a qualitative study

Background: The study aimed to investigate the meaning patients assign to two measures of quality of life: the Schedule for Evaluation of Individual Quality of Life Direct Weighting (SEIQoL-DW) and the SEIQoL-DW Disease Related (DR) version, in a clinical oncology setting. Even though the use of quality of life assessments has increased during the past decades, uncertainty regarding how to choose the most suitable measure remains. SEIQoL-DW versions assesses the individual's perception of his or her present quality of life by allowing the individual to nominate the domains to be evaluated followed by a weighting procedure resulting in qualitative (domains) as well as quantitative outcomes (index score). Methods: The study applied a cross-sectional design with a qualitative approach and collected data from a purposeful sample of 40 patients with gastrointestinal cancer. Patients were asked to complete two measures, SEIQoL-DW and the SEIQoL-DR, to assess quality of life. This included nomination of the areas in life considered most important and rating of these areas; after completion patients participated in cognitive interviews around their selections of areas. Interviews were audiotaped and transcribed verbatim which was followed by analysis using a phenomenographic approach. Results: The analyses of nominated areas of the two measures resulted in 11 domains reflecting what patients perceived had greatest impact on their quality of life. Analysis of the cognitive interviews resulted in 16 thematic categories explaining the nominated domains. How patients reflected around their quality of life appeared to differ by version (DW vs. DR). The DW version more often related to positive aspects in life while the DR version more often related to negative changes in life due to having cancer. Conclusions: The two SEIQoL versions tap into different concepts; health-related quality of life, addressing losses and problems related to having cancer and, quality of life, more associated with aspects perceived as positive in life. The SEIQoL-DR and the SEIQoL-DW are recommended in clinical practice to take both negative and positive aspects into account and acting on the problems of greatest importance to the patient