The Use of Visual Analogue Scale Score as a Predicting Tool in Differentiating Renal Colic From Lumbar Back Pain

Introduction Renal colic is often confused with low back pain (LBP) and other pathologies. Computed tomography (CT) is frequently used to reach a definitive diagnosis, but its use increases the exposure to radiation. Researchers have tried to predict urinary stones in patients presenting with flank pain. Several scoring systems have been introduced; however, none of them provide a prediction based on the physical examination of the patient upon initial presentation to the outpatient clinic. In this study, we aimed to investigate whether we can predict the presence of stone with visual analogue scale (VAS) questionnaire during the first admission. Materials and methods Patients with complaints of flank pain were started to be followed for three months in our urology clinic. After the definitive diagnosis was made the patients were classified into two groups: renal colic group (group 1; n=36) and the LBP group (group 2; n=30). Results In logistic regression analysis, the possibility of renal colic increased 5.4 times more per one-unit increase in the VAS score. In receiver operating characteristic (ROC) analyses, when the VAS was 4.5, the diagnosis of renal colic could be made with 88% sensitivity and 71% specificity. Conclusion If the VAS score is ≤ 4 in patients that have flank pain without limitation of movement, it is more likely to manage these patients with a simple medical treatment plan. In these patients, unnecessary ultrasonography (US) scans be reduced by 86.3% and unnecessary CT scans by 88.8%. A VAS score of ≥5 should warn the clinician about the necessity of routine urinary stone examinations.