Interrater Reliability of a Manual Diagnostic Protocol for Pancreatic Functional Visceral Dysfunction.

Background: A reliable manual examination has not been validated as a diagnostic tool for nociplastic visceral pain. Aims: To establish the interrater reliability of a manual examination protocol for functional pancreatic visceral dysfunction and the clinical criteria for a manual palpatory diagnosis based on the clinical features of the nociplastic visceral pain. Methods: This double-blind cross-sectional study involved 60 participants assessed by three raters using a manual protocol for diagnosing functional pancreatic visceral dysfunction. Five palpation-based criteria were evaluated: (1) local pain, (2) referred pain, (3) neurovegetative symptoms, (4) hyperalgesia or allodynia, and (5) tissue resistance/density. Interrater agreement was measured using percentage agreement and Fleiss' kappa. The reliability of the Verbal Numerical Rating Scale (vNRS) was assessed using the intraclass correlation coefficient (ICC). Repeated measures analysis of variance and Cochran's Q test (with Bonferroni correction) were used to analyze vNRS scores and categorical outcomes, respectively. Significance was set at p < 0.05. Results: Criteria 1, 3, and 4 showed particularly high levels of agreement, with overall agreement percentages of 93.3%, 95.6%, and 95.6%, respectively. The corresponding Fleiss' kappa values were 0.863, 0.880, and 0.908, indicating almost perfect agreement. In contrast, Criteria 2 and 5 demonstrated substantial, but comparatively lower, agreement, with overall percentages of 86.7% and 87.8% and Fleiss' kappa values of 0.679 and 0.755. The vNRS demonstrated excellent reliability across all three pancreas regions, with ICC values well >0.90: head (ICC = 0.943, 95% confidence interval [CI] = 0.913-0.964), body (ICC = 0.950, 95% CI = 0.923-0.968), and tail (ICC = 0.963, 95% CI = 0.944-0.977). Conclusions: Three blinded raters reached an almost perfect pair-wise interrater agreement on the presence or absence of functional visceral dysfunction in the topographic projection of the pancreas. This study provides preliminary evidence that a manual diagnostic protocol is a reliable and potentially useful diagnostic tool in diagnosing nociplastic pain in the topographic projection of the pancreas. Future research should prioritize evaluating the validity of the nociplastic visceral pain diagnosis.