The Impact of Psychological Factors on Complex Regional Pain Syndrome Type-1

Abstract

Background: To date, very little research has assessed the outcomes of CRPS, relationships between psychological factors, pain and disability in CRPS, and the influence of psychological factors on the recovery process. This thesis therefore had three aims: 1.) To investigate the long-term outcomes of CRPS, 2.) To measure associations between psychological factors, pain and disability in CRPS, and 3.) To determine whether psychological factors are associated with future outcomes in CRPS. Methods: 1.) A systematic review was conducted to investigate the outcomes of CRPS. 2.) A cross-sectional study was undertaken comparing chronic CRPS and low back pain patients in terms of the strength of associations between psychological factors, pain and disability. 3.) Cross-sectional data was utilised to assess the influence of psychological factors on disability and work status amongst acute CRPS patients. 4.) The same sample were followed prospectively for 12 months to determine the extent of symptomatic recovery, and to assess associations between baseline psychological factors and the outcomes of CRPS. Results: 1.) The systematic review revealed inconsistencies in the literature. Whilst previous prospective studies demonstrated good outcomes in CRPS patients, retrospective and cross-sectional studies revealed high rates of chronic pain and disability. 2.) The cross-sectional study found that amongst CRPS compared to low back pain patients, stronger associations existed between psychological factors, pain and disability. 3.) Amongst the acute CRPS sample, depression was associated with greater disability and sick leave. 4.) The prospective study showed lower rates of recovery amongst CRPS patients than previously documented. It also demonstrated that those with higher levels of anxiety, pain-related fear and disability at baseline exhibited a poorer recovery, with greater pain and disability over 12 months. Conclusions: The body of research showed that, in contrast with previous prospective studies, CRPS patients seldom make a complete recovery. Moreover, psychological factors are associated with greater pain and disability concurrently and are also associated with poorer long-term recovery. In future, researchers may wish to develop screening tools to identify those at risk of poor outcomes and/or develop early intervention treatments to prevent poor outcomes.