Latent anger profiles in chronic pain and their associations with current and long-term pain outcomes

Anger is prevalent in chronic pain (CP), often co-occurring with heightened distress and disability. The complexity of the anger construct manifests in heterogeneity of how anger is experienced, expressed, and regulated. Nevertheless, most work does not consider the inter-relationships between multiple dimensions of anger, limiting understanding of how anger might differentially contribute to pain outcomes. Here, various anger metrics and latent profile analysis (LPA) were utilized to identify disparate anger profiles in people with CP. Whether these profiles associated cross-sectionally and longitudinally with pain outcomes was subsequently examined. Data was collected from 735 treatment-seeking adult patients with CP of varied etiologies, of which 242 also completed follow-up assessments about 5 months after baseline. Anger measures included state and trait anger, anger expression (anger-in, anger-out), anger control (control-in, control-out), and perceived injustice. Pain outcomes included pain- intensity, distribution, interference, and behavior, and physical function. LPA identified four distinct anger profiles characterized by the combination of varying levels (low, medium, high) of anger and of perceived injustice. These profiles significantly associated with pain outcomes at both baseline and follow-up, above and beyond anxiety and depression. Profiles with medium-to-high levels of both anger (state, trait, and expression) and perceived injustice predicted the worst pain outcomes, suggesting that injustice-based profiling should be prioritized for anger-related stratification of risk in CP. The mechanistic and prognostic value of these anger profiles suggests that early assessment could enhance long-term treatment planning and advance personalized pain care, further emphasizing the need for tailored, anger-focused, patient-specific interventions.