Perceived Injustice in Patients With Chronic Pain: Prevalence, Relevance, and Associations With Long-Term Recovery and Deterioration

Abstract

The Injustice Experience Questionnaire (IEQ) assesses the degree to which chronic pain sufferers perceive injustice in relation to their pain. The aim of the current study was to assess the prevalence and relevance of the IEQ and its association to perceived recovery and deterioration in a naturalistic pain clinic population. Data was obtained from the Oslo University Hospital's Pain Registry. Among 2,950 patients, the prevalence of low (<19), medium (19-29) and high (30+) IEQ was 39%, 32% and 29% respectively. High levels of injustice were positively associated with a wide range of adverse health outcomes. Differences between those with high vs low levels of IEQ were clinically significant for most health outcomes. A Venn diagram analysis showed considerable, but not complete, overlap between IEQ, pain catastrophizing, psychological distress and severe pain intensity. High IEQ was associated with reduced clinical recovery (OR 0.6, 95% CI 0.4-0.9) and deterioration (OR 3.6, 95% CI 2.1-6.2) at 12-months follow-up, however, not when controlling for pain-related disability and pain intensity. We conclude that perceived injustice is a prevalent and clinically relevant phenomenon in a chronic pain clinic population, and that more knowledge is needed regarding its role as indicator of poor prognosis and target for tailored treatment. PERSPECTIVE: This article shows that pain-related injustice is both prevalent and relevant in a large naturalistic pain clinic population. Higher levels of injustice were consistently associated with adverse pain outcomes. Injustice could as such be a viable target for treatment of chronic pain, with potential indirect effects on pain and disability.

Keywords: IEQ; Injustice Experience Questionnaire; Perceived injustice; pain clinic population; pain registry.