Background: The STONE score has traditionally been used as a clinical prediction tool to predict the presence of ureteric stones in patients presenting with renal colic. More recently, the CHOKAI score was introduced and found to have superior diagnostic accuracy on both internal and external validation.

Objective: Our study aims to externally validate and compare the use of both the CHOKAI and STONE score in a population of UAE patients presenting to the Emergency Department for renal colic.

Methods: Over a period of approximately 6 months, the study will follow Emergency Department Physicians at each institution and retrieve data from their encounters with patients presenting with renal colic. Parameters for both CHOKAI and STONE scores will be logged, extracted and matched against a reference standard of CT scan to compare diagnostic accuracy of both scores to predict the presence of ureteric stones in this population.

Goals: Evaluation of the findings will discern applicability of scores to the UAE population and contribute to reducing unnecessary radiation exposure.

To our knowledge, no studies have compared the use of these scores to diagnose urolithiasis in the United Arab Emirates. Furthermore, this will be the first study to externally validate the CHOKAI score outside of Japan using a controlled, prospective design.

Over a period of approximately 6 months, the study will follow Emergency Department Physicians at each of three separate institutions and retrieve data from their encounters with patients presenting with renal colic. Parameters for both CHOKAI and STONE scores will be logged, extracted and matched against a reference standard of CT scan to compare diagnostic accuracy of both scores to predict the presence of ureteric stones in this population

Full-time ED Physicians from each institution will be recruited to participate in the study as follows:

Each ED Physician shall be provided with Data Collection Sheet. This form will provide them with a standardized option to enter the components of the STONE and CHOKAI score using data normally conducted in the history taking and physical examination of patients suspected to have ureteric stones. Additional items have also been included to investigate for other variables that could influence clinical prediction of presence of ureteric stones.

Those patients suspected to have ureteric stones will have confirmation of urolithiasis by non-contrast CT scan. Though the investigators will log the data in their respective data collection sheets per patient, they will not be involved in entering this data onto the study's database.

Data will be collected for a period of approximately 6 months from February 1, 2021 onward, with a target sample size of 200 patients.

Inclusion Criteria:

• Adult population (≥18 years of age) presenting to the Emergency Department with symptoms determined by the investigating ED Physician to be suspicious of urolithiasis (e.g. flank pain, lower abdominal pain, back pain and/or hematuria)
• Patients suspected to have ureteric stone who underwent CT scan to confirm diagnosis

Exclusion Criteria:

Complicated ureteric colic:

• Abnormal vital signs - body temperature > 37.7 °C or systolic blood pressure ˂90 mmHg)
• Active malignancy
• Abnormal kidney function (abnormal levels of creatinine/BUN)
• Recent (within past 6 months) trauma or urologic surgery
• Age <18 years
• Pregnant patient
• Patient with incomplete interview/documentation data (e.g. missing US/CT/ UA)

Adult patients presenting to the Emergency Department with symptoms suspicious of urolithiasis

The protocol for selection of patients used for prospective data collection shall be made available for the entirety of the study duration, including the Informed Consent Form we will use during patient encounters. The Statistical Analysis Plan (SAP) will be shared after results are compiled (approximately in 6 months from study start date) and processed by the biostatistician for a period of 3 months

Protocol and Informed Consent data will be available for 6 months from study start date Study Analysis Plan (SAP) will be available for 3 months once data collection is completed and results compiled for analysis

Any interested researcher can approach the Principal Investigator, Mohammad Anzal Rehman, at chokai.study@outlook.com for any of the details listed above within the time frames mentioned for access to the same.