Comparing the contribution of psychological inflexibility and coping measures to explain adjustment to cancer

Background: Psychological inflexibility (PI) is a core construct in Acceptance and Commitment Therapy. It refers to the inability to persist or change behavior in the service of chosen life values. PI is related to enhanced psychological distress (PD) and diminished psychological well-being (PWB) in patients with cancer. However, little is known about the predictive power of PI over well-established predictors of adjustment such as coping among patients with cancer. This study compared the relative utility of PI and coping in predicting PWB and PD. Methods: Participants were 128 patients with cancer (86.6% females; mean age = 50.6; SD = 9.8) recruited from the Oncology and Breast Cancer Centres of the Santa Chiara Hospital of Pisa (Italy). Participants completed self-report measures of PI (Action and Commitment Questionnaire-II, AAQ-II), coping (Brief COPE Inventory), PD (Hospital Anxiety and Depression scale), and PWB (Psychological Well-Being Scale). Results: The results from Hierarchical Regression Analyses indicated that PI significantly contributed to explain PD and PWB above and beyond measures of coping. Furthermore, while coping scores accounted for 9.2% to 23% of the variance in PD and PWB scores, PI accounted for 22% to 35% of the variance in outcome measures. Conclusions: Findings support the incremental validity of PI to explain adjustment to cancer above and beyond coping. Furthermore, findings suggest that PI (as measured by the AAQ-II) is a more useful construct than coping (as measured by the Brief COPE) to predict PD and PWB in patients with cancer