MIMIC: A pilot study for a randomised controlled trial of a risk calculator predicting stone clearance in acute ureteric colic

Abstract

Aim: The BURST MIMIC study showed that 25% of patients discharged with conservative management of a ureteric stone were re admitted for surgery. We aim to determine the feasibility of a randomised controlled trial for the use of a risk calculator predicting stone passage in acute ureteric colic patients with a view to a full trial to determine if use of the calculator improves outcomes and patient satisfaction. Population inclusion: Patients (age>18) with a new hospital presentation of acute ureteric colic due to radiologically confirmed urolithiasis. Patient suitable and willing to undergo conservative management of ureteric stone. Exclusion: Uncontrolled Pain Stone>10 mm Pyrexia/sepsis Adverse radiological findings Bilateral ureteric stones Single functioning kidney Intervention: A risk calculator developed from the 4181 patient MIMIC study cohort (online ± smart device), predicting stone passage and complication rate. The calculator will be used to inform the clinicians decision regarding intervention or conservative management and to aid in the counselling of patients. We propose a cluster randomised controlled trial to prevent learning bias. Comparator: Standard of care (no calculator) Feasibility Outcomes Estimate on time to stone and tube free Ease calculator use Lost to followup rate Determine predicted value of spontaneous stone passage at which point clinicians would recommend and/or patients would chose immediate intervention. Full Study Outcomes: Primary: Time to confirmation of stone clearance (stone free either clinical or imaging based) and free of all stents and nephrostomies. Secondary: The 90day rate of hospital readmission for intervention after conservative management for ureteric colic. The 90day rate of stone related complications QoL and patient satisfaction as measured by validated PROMS questionnaires.