AK Rohat, MD 1, Erdem Kurt, MD , Çağdaş Şenel, MD 3

1 Kartal Dr. Lütfi Kırdar City Hospital, Department of Emergency Medicine, Istanbul, Turkey 

2 İstanbul Education and Research Hospital, Department of Emergency Medicine, İstanbul, Turkey 

3 Balıkesir University, Department of Urology, Balıkesir, Turkey 

1. Introduction

 Renal colic is an emergency symptom characterized by sudden onset of intense pain secondary to urinary stone disease. It is the most common urologic disease of patients seeking help in the emergency department (ED) [1]. The overall prevalence of urinary stone disease is reported as 14% in Turkey [2]. In the United States, over 1 million patients are examined and treated for renal colic every year [3]. Use of unenhanced helical computed tomography (CT) is recommended for diagnosis of kidney stone disease due to its high sensitivity and specificity [4]. In the United States, more than 1.5 million CT scans are carried out yearly for suspected kidney stones [5]. Scoring systems have been developed for patients presenting to the ED with renal colic in order to reduce average time spent in the ED and reduce exposure to radiation. Moore et al. developed the STONE scoring system, comprised of 5 variables (sex, pain duration, ethnic origin, nausea-vomiting, hematuria) resulting in a score between 0 and 13 points. Scores ranging from 0 to 5, 6–9, and 10–13 represent a low, medium, and high risk of kidney stones respectively. In STONE scoring system's prospective validation, in patients with a score between 10 and 13, thus belonging to the high risk group, 88.6% were found to have a ureteral stone while only 1.6% received an alternative major diagnosis [6]. Fukuhara et al. developed the CHOKAI scoring system based on a Japanese population, comprised of seven variables (nausea-vomiting, hydronephrosis, hematuria, history of renal stones, sex, age, duration of pain). This system also scores patients from 0 to 13 points. In the study patients were seperated into two risk groups according to respective optimal cut-off values; CHOKAI score suggestive of high probability (6–13), and low probability (0–5). 98.6% of patients with CHOKAI scores ≥6 were found to have ureteral stones [7]. Our study aimed to compare and contrast the diagnostic accuracy of STONE and CHOKAI scores in patients presenting to the ED with flank pain. 

2. Materials and methods 

2.1. Study design and selection of patients 

The study facility was a 150-bed urban hospital with an annual ED census of approximately 216,000. The institutional review board approved the analysis and issued a waiver of consent (Ethics Committee Ruling number: 2019/8–4). We retrospectively reviewed the medical records of patients who visited the ED for flank pain between January 2019 and October 2019. Of these patients, those who were ≥ 15 years of age and had a urinalysis, ultrasonography (US) and CT scan available were included in the study. Patients with abnormal vital signs (high fever, hypotension), malignity history, urinalysis revealing leukocytes and C-reactive protein (CRP) concentrations ≥6 mg/L, and/or no US, CT, or urinalysis available were not included in the study. The definitive diagnosis of ureteral stone was made by a radiology specialist's analysis of CT scans. STONE and CHOKAI scores were calculated after diagnosis of urinary sytem stone was certain (Table 1) [6,7].