Whole Body Pain Distribution and Risk Factors for Widespread Pain Among Patients Presenting with Abdominal Pain: A Retrospective Cohort Study

INTRODUCTION: Abdominal pain frequently co-occurs with pain in other body sites. Chronic overlapping pain conditions (COPCs) represent a group of widespread pain diagnoses. Our study characterized how patterns of somatic pain distribution are associated with COPCs and aimed to characterize predictors of widespread pain among patients with chronic abdominal pain. METHODS: This retrospective cohort study included adults presenting to a tertiary pain clinic, reporting abdominal pain at their initial visit, and with a follow-up visit at 12 months. Body maps divided patients into localized, intermediate, and widespread pain distribution patterns. Diagnostic and psychosocial measures were assessed across groups at the initial and follow-up visits. We analyzed the association of baseline diagnoses and demographics and time-varying changes in psychosocial measures from initial to follow-up visit with changes in pain distribution over time with alternating logistic regression (ALR). RESULTS: Among 258 patients, most were female (91.5%) and reported widespread pain (61.5%). Those with widespread pain at baseline reported elevated anger and 60.0% of patients remained in the same pain category at follow-up. Multivariable ALR demonstrated higher pain interference (AOR 1.06, 95% CI 1.02–1.10, P = 0.002), higher anxiety (AOR 1.05, 95% CI 1.01–1.09, P = 0.01), more than one COPC at initial visit (AOR 2.85, 95% CI 1.59–5.11, P = 0.0005), and initial visit widespread pain categorization (AOR 4.18, 95% CI 2.20–8.00, P < 0.0001) were associated with an increased risk of widespread pain at the follow-up visit. CONCLUSION: Most patients with abdominal pain report additional pain locations at multiple other body sites, and non-localized pain persists 12 months after pain treatment. Screening for widespread pain and COPC at the initial visit may identify patients at higher risk for persistent or new-onset widespread pain, and interventions to reduce pain interference and anxiety may promote reversal of widespread pain.