The Impact of Timing of Definitive Intervention for Patients with Acute Renal Colic: A Population-Based Study.

Objective: To determine the impact of early intervention (EI) vs delayed intervention/expectant management for patients presenting to the emergency department (ED) with renal colic. Methods: We conducted a population-based cohort study in Ontario, Canada, utilizing linked administrative health data. Patients presenting to an ED with renal colic between April 1, 2010, and June 30, 2020, were included. Patients were divided into two groups. The EI group underwent shockwave lithotripsy, ureteroscopy, or percutaneous nephrolithotomy within 2 weeks of presentation. The delayed intervention/expectant management (non-EI) group represented all other patients, including those who did not receive intervention. Patients were followed forward in time for 3 months in the EI group and for 4 weeks postintervention or 3 months (whichever was longer) in the non-EI group, to assess for our outcomes. The outcomes included additional ED visits, hospitalizations, or imaging studies, stent/nephrostomy insertion, and urologist/primary care visits. These outcomes were compared across the two groups using a propensity score-matched generalized linear model with generalized estimating equations. Results: There were 397,185 index renal colic events (after propensity score matching EI = 27,741, non-EI = 80,230). The EI group had a lower risk for additional ED visits (relative risk (RR): 0.70, 95% confidence interval (CI): 0.68-0.72, p < 0.001) and hospital admissions (RR: 0.52, 95% CI: 0.50-0.55, p < 0.001) compared with the non-EI group. Similarly, the EI group had a lower risk for stent (RR: 0.62, 95% CI: 0.54-0.71, p < 0.001) or nephrostomy insertion (RR: 0.49, 95% CI: 0.42-0.57, p < 0.001), however, there was no difference for additional imaging. The EI group had a slightly increased risk for urologist/primary care visit (RR: 1.02, 95% CI: 1.02-1.03, p < 0.001). In the non-EI group, 17.31% underwent eventual intervention. Conclusion: Our study demonstrated a benefit to EI for those presenting with renal colic to the ED, but potentially with the risk of exposing some patients to unneeded treatment. These findings could influence practice patterns and guideline recommendations.