Associations between compensable injury, perceived fault and pain and disability 1 year after injury: a registry-based Australian cohort study

OBJECTIVES: Compensable injury increases the likelihood of having persistent pain after injury. Three-quarters of patients report chronic pain after traumatic injury, which is disabling for about one-third of patients. It is important to understand why these patients report disabling pain, in order to develop targeted preventative interventions. This study examined the experience of pain and disability, and investigated their sequential interrelationships with, catastrophising, kinesiophobia and self-efficacy 1 year after compensable and non-compensable injury. DESIGN: Observational registry-based cohort study. SETTING: Metropolitan Trauma Service in Melbourne, Victoria, Australia. PARTICIPANTS: Participants were recruited from the Victorian State Trauma Registry and Victorian Orthopaedic Trauma Outcomes Registry. 732 patients were referred to the study, 82 could not be contacted or were ineligible, 217 declined and 433 participated (66.6% response rate). OUTCOME MEASURES: The Brief Pain Inventory, Glasgow Outcome Scale, EuroQol Five Dimensions questionnaire, Pain Catastrophising Scale, Pain Self-Efficacy Questionnaire, Injustice Experience Questionnaire and the Tampa Scale of Kinesiophobia. METHODS: Direct and indirect relationships (via psychological appraisals of pain/injury) between baseline characteristics (compensation, fault and injury characteristics) and pain severity, pain interference, health status and disability were examined with ordinal, linear and logistic regression, and mediation analyses. RESULTS: Injury severity, compensable injury and external fault attribution were consistently associated with moderate-to-severe pain, higher pain interference, poorer health status and moderate-to-severe disability. The association between compensable injury, or external fault attribution, and disability and health outcomes was mediated via pain self-efficacy and perceived injustice. CONCLUSIONS: Given that the associations between compensable injury, pain and disability was attributable to lower self-efficacy and higher perceptions of injustice, interventions targeting the psychological impacts of pain and injury may be especially necessary to improve long-term injury outcomes.