Peace, equanimity and acceptance in the cancer experience: validation of the German version (PEACE-G) and associations with mental health, health-related quality of life and psychological constructs.

Background: Systematic reviews and meta-analyses reveal the importance of an accepting attitude towards cancer for mental health and functional coping. The aim of this study was to examine the psychometric properties of the German translation of the Peace, Equanimity, and Acceptance in the Cancer Experience (PEACE) questionnaire (Mack et al., 2008) and to investigate its associations with mental health, health-related quality of life (HRQoL) and related constructs.

Methods: The German version of the PEACE (PEACE-G) was created and validated with cancer patients in a cross-sectional two center questionnaire study. Construct validity was tested with confirmational factor analyses (CFA); Cronbach's alpha was used to determine internal consistency of items. We further examined associations with depression (PHQ-8), anxiety (GAD-7), distress (NCCN distress thermometer), HRQoL (SF-12), psychological flexibility (AAQ-II), resilience (RS-11) and acceptance scales, to evaluate concurrent and divergent validity.

Results: N = 213 cancer patients with different tumor entities participated in this study. Results of the CFA replicated the two-factor solution of the original PEACE (peaceful acceptance and struggle with illness) with satisfactory psychometric properties. Peaceful acceptance showed negative associations with depression, anxiety, distress, psychological inflexibility, and positive associations with HRQoL, acceptance, resilience, and mindfulness. Results of sensitivity analyses indicate a third factor (injustice/anger).

Conclusions: The results demonstrate the validity and reliability of PEACE-G in cancer patients and point to the essential role of acceptance- and mindfulness-based interventions in psycho-oncology. Further studies are needed to investigate the different facets of struggle with the cancer illness.