Follow-up study on the psychological aspects of chronic pain : quantitative and qualitative correlates of outcomes at one year

Abstract

Objective: Chronic back pain is highly prevalent in orthopaedic clinics. The aim of the study was to investigate the relationship of psychological factors affecting disability and distress outcomes in chronic low back pain patients. Clinicians shared the impression that chronic pain patients resulted from Injury on Duty (IOD) were particularly difficult to manage. Profiles of IOD patients and non-IOD patients were compared.

Methods: The present study is a prospective follow-up study. Fifty-four patients from a public orthopaedic out-patient clinic were assessed with low back pain as their primary complaint. Self-report inventories together with semi-structured interview were used to assess patients’ pain intensity, pain disability, psychological distress, positive and negative affect, as well as relevant pain-related parameters including pain catastrophizing thought, pain-related fear, pain self-efficacy and chronic pain acceptance. Patients were interviewed during their first visit to the orthopaedic out-patient clinic (i.e. Time 1), after 6 months (i.e. Time 2) and after 1 year (i.e. Time 3) of the first consultation. Both qualitative and quantitative analyses were conducted.

Results: Chronic pain acceptance predicted mid-term and long-term pain disability and psychological distress at a period of one year after their initial assessment. However, the pain-related parameters of pain catastrophizing, pain-related fear and pain self-efficacy did not show a significant predictive effect on outcomes. Pain rating is an inadequate estimate to assess patients’ level of disability and psychological status. The meaning of pain is important for patients to make sense of their pain experience and employ appropriate coping strategies. Attaching a positive value to pain helps patients to accept their pain. In addition, half of the chronic pain patients showed a need for psychiatric services at one year follow-up, pointing to a high co-morbidity between chronic pain and psychiatric problems.

Among the 54 patients, 17 (31.5%) were injured on duty (IOD). More IOD patients than non-IOD patients took sick leaves or were not working during the year. However, there is no significant difference between IOD group and non-IOD group on psychological distress, pain disability and other pain-related measures across 3 time points.

Discussion and Conclusion: Pain problems in the context of chronic pain are different from those in the context of acute pain. Intervention focusing on pain relief is inadequate to treat patients’ chronic pain. A multi-factorial perspective is needed to understand and develop suitable models to account for chronic pain experience instead of just relying on the prevalent fear-avoidance model. A more comprehensive assessment that is tailored to patients’ needs is necessary for more effective rehabilitation. Chronic pain patients’ need for psychiatric intervention is also highlighted, with a focus on work-related issues for IOD patients.