Children's and adolescents' relationship to pain during cancer treatment: a preliminary validation of the Pain Flexibility Scale for Children

Objectives: Children with cancer often suffer from pain. Pain is associated with psychological distress, which may amplify the pain experience. In chronic pain, it has been shown that psychological acceptance is helpful for both adults and children. For experimentally induced pain, interventions fostering psychological acceptance have been shown to predict increases in pain tolerance and reductions in pain intensity and discomfort of pain. A single subject study aiming to nurture psychological acceptance for children with cancer experiencing pain has shown promising results. No instruments measuring psychological acceptance in acute pain are yet available. The aim of the current study was to develop and preliminarily evaluate an instrument to measure psychological acceptance in children experiencing pain during cancer treatment. Methods: A test version of the Pain Flexibility Scale for Children was sent to all children aged 7-18 years undergoing cancer treatment in Sweden at the time of the study. Exploratory factor analysis was used. Internal consistency, test-retest reliability, and convergent validity were examined. Results: Sixty-one children participated in the study. A two-factor solution with Promax rotation was found to best represent the data. Internal consistency was good to excellent (alpha = 0.87-0.91). The total scale and the subscales demonstrated temporal stability (Intraclass correlation coefficient = 0.56-0.61) and satisfactory convergent validity (r=-0.27 to -0.68). Discussion: The Pain Flexibility Scale for Children measuring psychological acceptance in children with cancer experiencing pain is now available for use. This enables the evaluation of acceptance as a mediator for treatment change in the context of acute pain in children with cancer, which in turn is a step forward in the development of psychological treatments to help children cope with the pain during these difficult circumstances. The scale shows good psychometric properties but needs further validation, particularly considering the small sample size.