Diagnostic Performance of Onset Characterization vs. Time-to-Peak Assessment in Acute Abdominal Pain.

Abstract

Accurate assessment of symptom onset is crucial for diagnosing acute abdominal pain, particularly to identify life-threatening conditions such as rupture, dissection, vascular occlusion, torsion, or perforation. However, the optimal method for evaluating pain onset remains unclear. To compare the diagnostic performance of two history-taking approaches for evaluating pain onset: sudden onset characterization, which asks whether the pain began suddenly, and time-to-peak assessment, which asks how long it took for the pain to reach maximum intensity, considering "instantaneous peak" responses as positive. Prospective diagnostic study at a single acute care hospital in Japan between December 2022 and October 2024. A consecutive sample of adult patients presenting with abdominal pain of 7 days' duration or less in the emergency department was assessed. The primary outcome was the presence of a target condition, defined as rupture, dissection, vascular occlusion, torsion, or perforation of an intra-abdominal organ, confirmed by contrast-enhanced computed tomography findings or clinical follow-up. Diagnostic measures including specificity, sensitivity, positive and negative predictive values, and likelihood and diagnostic odds ratios were calculated for each approach. Of the 629 patients (median age, 58 years [interquartile range (IQR), 44-72 years]; 48.5% male), 20 (3.2%) were diagnosed with a target condition. Specificity improved from 86.7% (95% confidence interval [CI], 83.8%-89.2%) with sudden onset characterization to 94.3% (95% CI, 92.1%-95.8%) with time-to-peak assessment (P < .001). Sensitivity was 40.0% (95% CI, 21.9%-61.3%) for sudden onset characterization and 30.0% (95% CI, 14.5%-51.9%) for time-to-peak assessment (P = .48). Time-to-peak assessment demonstrated higher specificity without a significant loss of sensitivity compared with sudden onset characterization. This approach may assist in ruling-in critical intra-abdominal conditions in patients with acute abdominal pain. However, neither method alone is sufficient to rule-out life-threatening conditions.