The Diagnosis and Management of Patients with Renal Colic across a Sample of US Hospitals: High CT Utilization Despite Low Rates of Admission and Inpatient Urologic Intervention

Abstract

ObjectivesSymptomatic ureterolithiasis (renal colic) is a common Emergency Department (ED) complaint. Variation in practice surrounding the diagnosis and management of suspected renal colic could have substantial implications for both quality and cost of care as well as patient radiation burden. Previous literature has suggested that CT scanning has increased with no improvements in outcome, owing at least partially to the spontaneous passage of kidney stones in the majority of patients. Concerns about the rising medical radiation burden in the US necessitate scrutiny of current practices and viable alternatives. Our objective was to use data from a diverse sample of US EDs to examine rates of and variation in the use of CT scanning, admission, and inpatient procedures for patients with renal colic and analyze the influence of patient and hospital factors on the diagnostic testing and treatment patterns for patients with suspected renal colic.MethodsWe conducted a retrospective cohort study of adult patients who received a diagnosis of renal colic via a visit to an ED at 444 US hospitals participating in the Premier Healthcare Alliance database from 2009–2011. We modeled use of CT, admission, and inpatient urologic intervention as functions of both patient characteristics and hospital characteristics.ResultsOver the 2-year period, 307,612 patient visits met inclusion criteria. Among these patients, 254,211 (82.6%) had an abdominal CT scan, with 91.5% being non-contrast (“renal protocol”) CT scans. Nineteen percent of visits (58,266) resulted in admission or transfer, and 9.8% of visits (30,239) resulted in a urologic procedure as part of the index visit. On multivariable analysis male patients, Hispanic patients, uninsured patients, and privately insured patients were more likely to have a CT scan performed. Older patients and those covered by Medicare were more likely to be admitted, and once admitted, white patients and privately insured patients were more likely to have a urologic intervention. Only hospital region was associated with variation in CT rates, and this variation was minimal. Region and size of the hospital were associated with admission rates, and hospitals with more practicing urologists had higher intervention rates.ConclusionsIn this dataset, the majority of patients did not require admission or immediate intervention. Despite this, the large majority received CT scans, in a cohort representing 15–20% of all US ED visits. The CT rate was minimally variable at the hospital level, but the admission rates varied 2-fold, suggesting that hospital-level factors affect patient management. The high rate of CT usage coupled with the low rate of immediate intervention suggests that further research is warranted to identify patients who are at low risk for an immediate intervention, and could potentially be managed with ultrasound alone, expectant management, or delayed CT.

The Accuracy and Prognostic Value of Point‐of‐care Ultrasound for Nephrolithiasis in the Emergency Department: A Systematic Review and Meta‐analysis

“…Over the past two decades, CT utilization has grown from 4% in 1996 to 1998, to over 45% in 2008 . A more recent study suggests that the rate of CT scanning may currently approach 80% in some centers . However, patients are subjected to ionizing radiation and its associated risks, as well as the possibility of clinically unimportant incidental findings .…”

Predictors of Hospital Admission and Urological Intervention in Adult Emergency Department Patients with Computerized Tomography Confirmed Ureteral Stones

“…Previous studies have shown significant variation in inpatient urologic procedures based on patients’ insurance status, race, day of presentation, and number of urologists operating at a hospital. 7,20,21 As such, the generalizability of our results to regions and institutions with different health systems or practice patterns is limited. Additionally, our study did not take into account the availability of low-dose CT, which alters the risk-benefit relationship for CT use, and does not address the issue of operator variability in the performance of ultrasound.…”

“…7 Guidelines for admitting patients with renal colic have not been well elucidated, though expert opinion recommends admission for stone emergencies such as co-existent obstructing stone and renal failure or evidence of urinary tract infection or uncontrolled pain. 7,18 Our results reflect these recommendations as markers of kidney injury, infection, antibiotic use, and intravenous opiate analgesia remained significant in regression models. It is worth noting that regression models had similar c-statistics whether or not CT findings such as stone size were included.…”

“…7,8 Predictors of hospital admission and/or subsequent need for urologic intervention in patients presenting with acute renal colic are not well defined. Prior studies on this topic have proposed numerous clinical, laboratory or radiologic variables as predictors, but have been limited by their small sample sizes, retrospective design or failed validation.…”

Imaging in Suspected Renal Colic: Systematic Review of the Literature and Multispecialty Consensus

“…The perspective of the urologist considering surgical intervention may differ from that of the clinician initially evaluating and treating the patient (often an emergency physician). Deciding whether patients with suspected renal colic need imaging during the initial evaluation and, if so, what type is an area with wide practice variation [7]. Although guidelines on "appropriate use" have been developed, they tend to emphasize CT without providing guidance on optimal imaging or scenarios in which CT may not be needed [8][9][10].…”