Measurement of Quality of Life in Palliative Care: Evidence for Criterion-Oriented Validity of a Single-Item Approach.

Abstract

Assessment of quality of life is of central importance in palliative care to understand patients' needs and improve their treatment. However, due to the severely compromised state of health of the severely ill or dying patients, the possibility of an adequate assessment with longer questionnaires is limited. Investigation of the criterion-oriented validity of a single item to measure quality of life in palliative care patients. In a cross-sectional study, correlations of the single item with established questionnaires were analyzed. At Malteser Hospital Bonn and Bonn University Hospital, 72 palliative patients, mainly suffering from cancer, were investigated. Clinical symptoms were measured by the Minimal Documentation System (MIDOS) and quality of life was assessed by the single item "How satisfied are you currently with your physical and emotional well-being?" on a 7-point scale as well as by the Functional Assessment of Cancer Therapy-General (FACT-G) and the Palliative Outcome Scale (POS). Seventy-one of 72 patients filled in the single item and the POS, 64 patients the FACT-G. There was a high correlation between the assessment of quality of life by the single item and the FACT-G (r = 0.695, p < 0.01) as well as the POS (r = -0.630, p < 0.01). The study confirms the criterion-oriented validity of the single item to measure quality of life in palliative care patients. This can be seen as a first step to validate this economic instrument. Future studies should focus on the analysis of further psychometric aspects (e.g., reliability, sensitivity to change) of the single item.