Accuracy of Pain Scales in Predicting Critical Diagnoses in Non-Traumatic Abdominal Pain Cases; a Cross-sectional Study

INTRODUCTION: Accurate assessment and management of abdominal pain in the emergency department (ED) is crucial, as it can indicate potentially life-threatening conditions requiring timely treatment. This study aimed to evaluate the ability of pain scales to predict critical diagnoses in patients with non-traumatic abdominal pain. METHODS: This cross-sectional study was conducted at a tertiary university hospital and involved individuals aged 15 years and above who presented to the ED with non-traumatic abdominal pain. Pain severity was evaluated using subjective pain scales, including the Numerical Rating Scale (NRS) and the Face Pain Scale (FPS), as well as objective pain scales, including the Critical Care Pain Observation Tool (CPOT) and the Non-verbal Pain Score (NVPS). The area under the receiver operating characteristic curve (AuROC) was employed to determine the discriminative ability of each pain scale to predict critical diagnosis. RESULTS: 264 cases with the mean age of 47.2±19.4 years were studied (53.0% male). The most common location of abdominal pain was epigastric pain (43.9%). Most patients presented with dull-aching pain, and those with critical diagnoses had more of this characteristic than those with non-critical diagnoses. (52.5% vs. 28.3%, p = 0.01). The overall median NRS, FPS, CPOT, and NVPS of included participants were 8 (interquartile range (IQR) 7-10), 8 (IQR 6-8), 3 (IQR 1-4), and 3 (IQR 2-4), respectively. Patients with critical diagnoses had a higher NVPS score than patients with non-critical diagnoses (median score of 4 vs. 3, p = 0.02). The AuROC of NRS, FPS, CPOT, and NVPS were 0.53 (95% CI: 0.45-0.62), 0.55 (95% CI: 0.46-0.63), 0.59 (95% CI: 0.50-0.68), and 0.62 (95% CI: 0.53-0.71), respectively. The correlation coefficients among these scales were considered moderately correlated or higher. CONCLUSION: In evaluating patients with non-traumatic abdominal pain, the NVPS demonstrated the highest accuracy in predicting critical diagnoses. However, all pain scales, whether subjective or objective, exhibited suboptimal performance in predicting critical diagnoses.