Measuring the psychosocial dimensions of quality of life in advanced cancer patients: psychometrics of the German Quality of Life at the End of Life–Cancer–Psychosocial (QUAL-EC-P) Questionnaire

Context: Quality of life (QoL) is a central focus of care in advanced cancer. Specialized instruments, such as the Quality of Life at the End of Life-Cancer (QUAL-EC), may be useful to assess psychosocial issues associated with QoL unique to this population. Objectives: To evaluate the measurement of the psychosocial dimensions of QoL using the German translation of the QUAL-EC-Psychosocial (QUAL-EC-P) questionnaire, including factor structure and psychometrics. Methods: About 183 patients with advanced cancer from the University Medical Center Hamburg-Eppendorf and University Medical Center Leipzig completed the QUAL-EC-P questionnaire. We conducted exploratory factor analysis as well as item and reliability analysis. We examined convergent validity with correlations between the scale and relevant psychological constructs. Results: The sample was 60% female with mean age of 57.7 (SD = 11.7). We extracted three factors accounting for 44% of the variance aligning with the structure of the instrument. The QUAL-EC-P questionnaire showed good to acceptable internal consistency for the QoL-psychosocial total score (α = 0.77), the Life completion subscale (α = 0.77), and the Relationship with health care provider subscale (α = 0.81). The Preparation for end of life subscale had adequate albeit low internal consistency (α = 0.64) because concerns about family were less associated with financial worry and fear of death than expected. The psychosocial dimensions of QoL correlated negatively with depression (r = −0.27, P ≤ 0.001), anxiety (r = −0.32, P ≤ 0.001), demoralization (r = −0.63, P ≤ 0.001), and attachment insecurity (r = −0.51, P ≤ 0.001) and positively with spiritual well-being (r = 0.63, P ≤ 0.001). Conclusion: The QUAL-EC-P questionnaire may be used to assess the psychosocial aspects of QoL and promote their clinical discussion in patients with advanced cancer