Interpretation of clinically meaningful change in cancer palliative care patients' quality of life: minimally important difference for EORTC QLQ-C15-PAL.

Abstract

Background: Palliative care for cancer helps improve and maintain patients' quality of life (QOL). Clinically meaningful changes in QOL measures are helpful when considering how a patient would want to spend the final days of their life. This study aimed to estimate the minimally important differences (MIDs) for within-person change for the European Organisation for Research and Treatment of Cancer QOL Questionnaire Core 15 Palliative Care (EORTC QLQ-C15-PAL) domains in advanced cancer patients in palliative care.

Method: Participants in this multicenter observational study comprised patients with advanced cancer receiving palliative care in the last year before death. The EORTC QLQ-C15-PAL was administered at two-week intervals. During the second assessment, patients also completed the Global Rating of Change (GRC) scale to collect their subjective assessments of changes in their condition since the first assessment. MID for QOL score with a correlation of 0.3 or more with GRC score changes were estimated using anchor- and distribution-based methods.

Results: Among the 257 screened patients at 13 facilities, we analyzed 181 (92 male; mean age: 67). The mean survival time was 131 days. Notably, the number of patients who responded "no change" for the GRC items was large (63-128). Anchor-based MIDs differed depending on the change direction (improvement vs. deterioration). The MIDs for meaningful within-person change may be used in clinical practice.

Conclusion: We estimated the MIDs in EORTC QLQ-C15-PAL in patients with advanced cancer with a life expectancy of less than one year, both anchor- and distribution-based.