The impact of pain cognitions on perceived disability in people with chronic pain

Chronic pain is a common condition that impacts on an individuals ability to engage in functional tasks such as self-care, domestic chores and paid work. In order to reduce the burden of chronic pain conditions, pain management clinicians and researchers have recognised the importance of identifying factors that contribute to the development and maintenance of chronic pain and disability. They have also articulated the need to assess the outcomes of pain management intervention using instruments that measure the impact of pain on daily functioning. Research over the years has consistently demonstrated a limited relationship between physical pathology and a persons functional abilities. However, studies that have approached pain using a biopsychosocial frame of reference have shown that pain cognitions, that is a persons beliefs, appraisals and expectancies regarding their pain, have a significant role in determining the impact of pain on an individuals capacity to manage pain and participate in daily activities and social roles. As such, there has been a multitude of research over the last two decades into the relationship between pain cognitions and the impact and experience of pain. Using a cross-sectional design, this study aimed to investigate the relationship between pain cognitions, specifically pain-related fear, catastrophising and selfefficacy, and levels of disability experienced by patients attending a Multidisciplinary Pain Centre. Disability was defined in accordance with the World Health Organisations International Classification of Functioning, Disability and Health (ICF) definition, that is a) activity limitation and b) participation restriction. The study also aimed to investigate the ICF domains of activity limitation and participation restriction to provide evidence that these concepts are separate constructs. One hundred and sixty-one patients with chronic pain of non-cancer origin attending a Multidisciplinary Pain Centre at a metropolitan tertiary hospital over a ten month period were recruited to the study. One hundred and twelve patients attending the inpatient pain management programme and 49 patients attending the outpatient pain management programme completed a battery of self-report questionnaires prior to the commencement of cognitive-behaviourally based multidisciplinary intervention. Self-report measures included the Tampa Scale for Kinesiophobia, Pain Catastrophising Scale, Pain Self-Efficacy Questionnaire, Disability Anxiety Stress Scales - 21, Spinal Function Sort and Pain Disability Index. Information related to pain intensity and duration and demographic factors such as age and employment status was also obtained. A series of hierarchical regression analyses were performed to determine the relationship between pain cognitions (pain-related fear, catastrophising and self-efficacy) and perceived disability. Variables were entered into the regression analyses in an apriori manner, based on substantive theory, in order to identify the unique predictive capacity of particular pain cognitions in predicting disability over and above the other pain cognitions included in the study. The findings of this study suggested that in predicting the impact of chronic pain on a persons ability to perform physical tasks and participate in life roles, pain cognitions should be considered over and above pain intensity, pain duration and certain demographic variables. Furthermore, the findings identified self-efficacy as a stronger predictor of perceived disability, that is of both activity limitation and participation restriction, than pain-related fear and catastrophising. This study also provided support for the developing area of research indicating that disability is a multifaceted concept, the components of which should be considered distinct constructs. This finding was evidenced by a modest relationship between activity limitation and participation restriction (r = .543). It was further demonstrated through two hierarchical regression analyses; one with activity limitation as the dependent variable and one with participation restriction as the dependent variable. Different predictive models with distinct predictive variables were identified for each ICF domain providing support that the concepts are separate constructs. The discussion in this thesis focuses on the exploration of research findings in the context of established literature in the field of chronic pain management. Suggestions are made for future research and opportunities to further enhance current clinical practice are considered. Factors that may have influenced the findings, included limitations of the study, are also discussed