Cost Analysis of the STONE Randomized Trial: Can Health Care Costs be Reduced One Test at a Time?

POCUS-first for nephrolithiasis: A Monte Carlo simulation illustrating cost savings, LOS reduction, and preventable radiation

OBJECTIVES

Non-contrast computed tomography (NCCT) is the gold standard for nephrolithiasis evaluation in the emergency department (ED). However, Choosing Wisely guidelines recommend against ordering NCCT for patients with suspected nephrolithiasis who are <50 years old with a history of kidney stones. Our primary objective was to estimate the national annual cost savings from using a point-of-care ultrasound (POCUS)-first approach for patients with suspected nephrolithiasis meeting Choosing Wisely criteria. Our secondary objectives were to estimate reductions in ED length of stay (LOS) and preventable radiation exposure.

METHODS

We created a Monte Carlo simulation using available estimates for the frequency of ED visits for nephrolithiasis and eligibility for a POCUS-first approach. The study population included all ED patients diagnosed with nephrolithiasis. Based on 1000 trials of our simulation, we estimated national cost savings in averted advanced imaging from this strategy. We applied the same model to estimate the reduction in ED LOS and preventable radiation exposure.

RESULTS

Using this model, we estimate a POCUS-first approach for evaluating nephrolithiasis meeting Choosing Wisely guidelines to save a mean (±SD) of $16.5 million (±$2.1 million) by avoiding 159,000 (±18,000) NCCT scans annually. This resulted in a national cumulative decrease of 166,000 (±165,000) annual bed-hours in ED LOS. Additionally, this resulted in a national cumulative reduction in radiation exposure of 1.9 million person-mSv, which could potentially prevent 232 (±81) excess cancer cases and 118 (±43) excess cancer deaths annually.

CONCLUSION

If adopted widely, a POCUS-first approach for suspected nephrolithiasis in patients meeting Choosing Wisely criteria could yield significant national cost savings and a reduction in ED LOS and preventable radiation exposure. Further research is needed to explore the barriers to widespread adoption of this clinical workflow as well as the benefits of a POCUS-first approach in other patient populations.

Outpatient management of moderate cellulitis in children using high-dose oral cephalexin

Objectives

To evaluate the effectiveness of a high-dose (HD) oral cephalexin treatment guideline for children with moderate cellulitis treated as outpatients.

Methods

In this retrospective cohort study, we included children who presented to the emergency department (ED) with moderate cellulitis and treated according to the institution’s HD oral cephalexin guideline over a 2-year period. All children had standardized follow-up at a medical day hospital (MDH). Treatment was considered effective in the absence of treatment failure, defined as admission, switch to IV treatment or ED visit within 2 weeks of discharge from the MDH. Safety was ascertained by recording adverse events and severe complications at follow-up.

Results

A total of 123 children were treated as outlined in the guideline, including 117 treated with HD oral cephalexin. The success rate was 89.7% (105/117). Among 12 (10.3%) children who had treatment failure, 10 (8.5%) required admission, 1 (0.9%) received IV antibiotics at the MDH and 1 (0.9%) had a return visit to the ED without admission. No severe complications were reported; four abscesses required drainage and one patient had a rash. The mean number of visits per child at the MDH was 1.6 (SD 1.0).

Conclusions

With a success rate of 89.7%, HD oral cephalexin seems effective and safe for the treatment of children with moderate cellulitis. Its use potentially reduces hospitalization rates for this condition and decreases the need for IV insertion.

Progression of asymptomatic nephrolithiasis in children: How often should patients receive follow-up ultrasound imaging?

INTRODUCTION

The natural history of asymptomatic nephrolithiasis (AN) in children is not well defined. Furthermore, there is no guidance on the utility of repeated renal ultrasound evaluations in this same population. Follow-up ultrasound studies are often obtained as frequently as every 6 months. The goal of this study is to assess the follow-up ultrasound interval in the management of these patients.

METHODS

A retrospective IRB approved chart review was performed for patients seen for non-cysteine AN between 2012 and 2019. AN was defined as patients without obstructive uropathy abdominal, flank pain and/or gross hematuria. Asymptomatic stones were discovered incidentally or after an acute stone event. Patients with pre-existing renal anomalies and the timepoints with stone passage or stone procedure were excluded. Descriptive statistics were used for demographic information. Multiple linear regression was used to analyze risk factors. Statistical significance was set to p < 0.05.

RESULTS

Twenty-nine patients had 90 ultrasounds. The average age at diagnosis was 10.8 ± 6.2 years. The average number of ultrasound studies per patient was 3.2 ± 1.7. The median time between follow-up ultrasounds was 5.2 months [IQR 2.8-10.0]. Median follow-up of patients was 10.6 months [IQR 4.9-21.9]. The change in total stone burden occurred at a rate of 0.11 mm/month (CI [-0.06-0.28], p = 0.20, r² = 0.42) or 0.66 mm/6 months. Patients with more renal stones had almost a threefold increase in stone burden compared to patients with fewer renal stones (2.98 [CI 1.34-4.62], p=0.001, r²=0.33). Patients with a family history of stones had a twofold increase in the size of their largest stone when compared to patients without a family history (1.97 [CI 0.26-3.68], p=0.02, r²=0.60.

CONCLUSION

A complex interplay of multiple factors influence the progression of AN in children. Children with a greater number of stones have a higher increase in total stone burden and children with a family history of stones have a faster increase in largest stone size. These patients may require more frequent imaging studies. The small change in stone size over time favors a longer than 6-month interval for many children.

Point-of-Care Ultrasound Use and Monetary Outcomes in a Single-Payer Health Care Setting

OBJECTIVES

Point-of-care ultrasound (POCUS) is a widely used diagnostic modality in the emergency physician's tool kit. The effect on health care costs is disputed. This study examined whether POCUS was associated with system-level cost savings. Secondary objectives included adverse patient outcomes and the association between POCUS use and diagnostic costs in specific patient groups.

METHODS

The Point-of-Care Ultrasound Use and Monetary Outcomes study was a single-center prospective observational study. A convenience sample of emergency medicine physicians working from July to October 2019 were included after using POCUS as part of their assessment. The cost of patient investigations was compared with those proposed by a control group of physicians simultaneously on shift, who were blinded to the POCUS findings. Ethical approval was obtained from the Queen's University Health Sciences Research Ethics Board.

RESULTS

Fifty patient assessments using POCUS were included. Overall, the median investigation cost in United States dollars in the POCUS group was $102.00 (interquartile range [IQR], $39.80-$167.90) versus $122.40 (IQR, $70.96-$175.60) in controls (P = .08). When stratified by disposition, POCUS use in patients discharged home resulted in a median expenditure of $71.80 (IQR, $36.48-$116.70) versus $122.70 (IQR, $71.18-$183.20; P < .001). Significant cost savings were also found in flank pain presentations (median, $138.90; IQR, $136.60-$186.10; P = .01). There were no differences in the quantity of investigations ordered, the patient emergency department repeated presentation rate, or safety outcomes at 7 days.

CONCLUSIONS

Point-of-care ultrasound use was not associated with significant cost savings in our overall population. The subgroup analysis revealed significant POCUS-associated cost savings in patients discharged home and those presenting with flank pain. Notably, POCUS was not associated with an increase in adverse patient safety outcomes.

What are the clinical effects of the different emergency department imaging options for suspected renal colic? A scoping review

OBJECTIVES

Clinicians have minimal guidance regarding the clinical consequences of each radiologic imaging option for suspected renal colic in the emergency department (ED), particularly in relation to patient-centered outcomes. In this scoping review, we sought to identify studies addressing the impact of imaging options on patient-centered aspects of ED renal colic care to help clinicians engage in informed shared decision making. Specifically, we sought to answer questions regarding the effect of obtaining computed tomography (CT; compared with an ultrasound or delayed imaging) on safety outcomes, accuracy, prognosis, and cost (financial and length of stay [LOS]).

METHODS

We conducted a comprehensive search using Pubmed, EMBASE, Web of Science conference proceedings index, and Google Scholar, identifying studies pertaining to renal colic, urolithiasis, and ureterolithiasis. In a prior qualitative study, stakeholders identified 14 key questions regarding renal colic care in the domains of safety, accuracy, prognosis, and cost. We systematically screened studies and reviewed the full text of articles based on their ability to address the 14 key questions.

RESULTS

Our search yielded 2570 titles, and 68 met the inclusion criteria. Substantial evidence informed questions regarding test accuracy and radiation exposure, but less evidence was available regarding the effect of imaging modality on patient-oriented outcomes such as cost and prognosis (admissions, ED revisits, and procedures). Reviewed studies demonstrated that both standard renal protocol CT and low-dose CT are highly accurate, with ultrasound having lower accuracy. Several studies found that ureterolithiasis diagnosed by ultrasound was associated with overall reduced radiation exposure. Existing studies did not suggest choice of imaging influences prognosis. Several studies found no substantial differences in monetary cost, but LOS was found to be shorter if a diagnosis was made with point-of-care ultrasound.

CONCLUSION

There is a plethora of data related to imaging accuracy. However, there is minimal data regarding the effect of CT on many patient-centered outcomes. Further research could improve the patient-centeredness of ED care.

A systematic review of the cost-effectiveness of ultrasound in emergency care settings

BACKGROUND

The use of ultrasound (US) in emergency departments (ED) has become widespread. This includes both traditional US scans performed by radiology departments as well as point-of-care US (POCUS) performed by bedside clinicians. There has been significant interest in better understanding the appropriate use of imaging and where opportunities to enhance cost-effectiveness may exist. The purpose of this systematic review is to identify published evidence surrounding the cost-effectiveness of US in the ED and to grade the quality of that evidence.

METHODS

We performed a systematic review of the literature following Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Studies were considered for inclusion if they were: (1) economic evaluations, (2) studied the clinical use of ultrasound, and (3) took place in an emergency care setting. Included studies were critically appraised using the Consolidated Health Economic Evaluation Reporting Standards checklist.

RESULTS

We identified 631 potentially relevant articles. Of these, 35 studies met all inclusion criteria and were eligible for data abstraction. In general, studies were supportive of the use of US. In particular, 11 studies formed a strong consensus that US enhanced cost-effectiveness in the investigation of pediatric appendicitis and 6 studies supported enhancements in the evaluation of abdominal trauma. Across the studies, weaknesses in methodology and reporting were common, such as lack of sensitivity analyses and inconsistent reporting of incremental cost-effectiveness ratios.

CONCLUSIONS

The body of existing evidence, though limited, generally demonstrates that the inclusion of US in emergency care settings allows for more cost-effective care. The most definitive evidence for improvements in cost-effectiveness surround the evaluation of pediatric appendicitis, followed by the evaluation of abdominal trauma. POCUS outside of trauma has had mixed results.

Assessing Cost-Effectiveness of New Technologies in Stone Management

Diagnosis, treatment, and follow-up are all influential in determining the overall cost to the health care system for kidney stones. New innovations in the field of nephrolithiasis have been abundant, including disposable ureteroscopes, ultrasound-guided approaches to percutaneous nephrolithotomy, and advanced laser lithotripters. Identifying cost-effective treatment strategies encourages practitioners to be thoughtful about providing value-based high-quality care and remains on important principle in the treatment of urinary stone disease.

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

INTRODUCTION

Point-of-care ultrasound (POCUS) has been suggested as an initial investigation in the management of renal colic. Our objectives were: 1) to determine the accuracy of POCUS for the diagnosis of nephrolithiasis and 2) to assess its prognostic value in the management of renal colic.

METHODS

The review protocol was registered to the PROSPERO database (CRD42016035331). An electronic database search of MEDLINE, Embase, and PubMed was conducted utilizing subject headings, keywords, and synonyms that address our research question. Bibliographies of included studies and narrative reviews were manually examined. Studies of adult emergency department patients with renal colic symptoms were included. Any degree of hydronephrosis was considered a positive POCUS finding. Accepted criterion standards were computed tomography evidence of renal stone or hydronephrosis, direct stone visualization, or surgical findings. Screening of abstracts, quality assessment with the QUADAS-2 instrument, and data extraction were performed by two reviewers, with discrepancies resolved by consensus with a third reviewer. Test performance was assessed by pooled sensitivity and specificity, calculated likelihood ratios, and a summary receiver operator curve (SROC). The secondary objective of prognostic value was reported as a narrative summary.

RESULTS

The electronic search yielded 627 unique titles. After relevance screening, 26 papers underwent full-text review, and nine articles met all inclusion criteria. Of these, five high-quality studies (N = 1,773) were included in the meta-analysis for diagnostic accuracy and the remaining yielded data on prognostic value. The pooled results for sensitivity and specificity were 70.2% (95% confidence interval [CI] = 67.1%-73.2%) and 75.4% (95% CI = 72.5%-78.2%), respectively. The calculated positive and negative likelihood ratios were 2.85 and 0.39. The SROC generated did not show evidence of a threshold effect. Two of the studies in the meta-analysis found that the finding of moderate or greater hydronephrosis yielded a specificity of 94.4% (95% CI = 92.7%-95.8%). Four studies examining prognostic value noted a higher likelihood of a large stone when positive POCUS findings were present. The largest randomized trial showed lower cumulative radiation exposure and no increase in adverse events in those who received POCUS investigation as the initial renal colic investigation.

CONCLUSION

Point-of-care ultrasound has modest diagnostic accuracy for diagnosing nephrolithiasis. The finding of moderate or severe hydronephrosis is highly specific for the presence of any stone, and the presence of any hydronephrosis is suggestive of a larger (>5 mm) stone in those presenting with renal colic.

Urinary Stone Disease: Diagnosis, Medical Therapy, and Surgical Management

Clinical suspicion of urolithiasis should be evaluated with low-dose computed tomography as the first-line imaging modality for nonpregnant, adult patients. A period of observation may be appropriate for ureteral stones less than 10 mm, and medical expulsive therapy may be beneficial for facilitating passage of distal ureteral stones. Regardless of stone type, patients should adhere to a low-sodium diet and attempt to achieve a urine volume of more than 2.5 L daily. Individuals with calcium stones should maintain a normal calcium diet, and if stones persist, citrate therapy or thiazide diuretics in the setting of hypercalciuria may be indicated.

Imaging Advances in Urolithiasis

The prevalence of urinary stones in the United States has been described as 1 in 11 persons reporting a history of stones. Imaging plays a crucial role in diagnosis, management, and follow-up for these patients and imaging technology over the last 100 years has advanced as the disease prevalence has increased. CT remains the gold standard for imaging urolithiasis and changes in this technology, with the addition of multidetector CT and dual-energy CT, as well as the changes in utilization of CT, have decreased the radiation dose encountered by patients and allowed for improved stone detection. The use of digital tomography has been introduced for follow-up of recurrent stone formers offering the potential to lower radiation exposure over the course of a patient's lifelong treatment. However, there is still a demand for improved imaging techniques to detect smaller stones and stones in larger patients at lower radiation doses as well as the continued need for the judicious use of all imaging modalities for healthcare cost containment and patient safety.

Trends in Imaging Use for the Evaluation and Followup of Kidney Stone Disease: A Single Center Experience

PURPOSE

Recent reports support renal ultrasound as the initial imaging study to evaluate patients with suspected renal colic. However, urologists often advocate for computerized tomography to better define stone size and location, especially before proceeding with endourological intervention. One concern with using ultrasound as initial imaging is that computerized tomography may be required later, obviating the reduction in costs and radiation gained by using ultrasound.

MATERIALS AND METHODS

We retrospectively reviewed the electronic health records of 10,680 episodes of stone disease in a total of 7,659 patients who presented to the emergency department or walk-in clinic with a chief complaint or visit diagnosis of urolithiasis from 2009 to 2015 at a single institution. Images obtained during the index encounter and in the following 90 days were recorded.

RESULTS

The index encounter included computerized tomography in 47% of episodes, ultrasound in 20%, plain x-ray of the kidneys, ureters and bladder in 12% and no imaging in 29%. Of the index visits 49% included multiple testing. If no computerized tomography was obtained during the index visit, 10% of patients underwent computerized tomography later in the episode. Total imaging costs and radiation exposure during 90 days were significantly higher when computerized tomography was done at the index visit. If the initial image obtained during an episode was ultrasound, computerized tomography was performed in 20% of cases within 90 days.

CONCLUSIONS

Of patients who underwent an initial ultrasound 80% avoided computerized tomography imaging. Avoiding computerized tomography at the index visit was associated with substantial reductions in radiation exposure and imaging costs.

An overview of kidney stone imaging techniques

Kidney stone imaging is an important diagnostic tool and initial step in deciding which therapeutic options to use for the management of kidney stones. Guidelines provided by the American College of Radiology, American Urological Association, and European Association of Urology differ regarding the optimal initial imaging modality to use to evaluate patients with suspected obstructive nephrolithiasis. Noncontrast CT of the abdomen and pelvis consistently provides the most accurate diagnosis but also exposes patients to ionizing radiation. Traditionally, ultrasonography has a lower sensitivity and specificity than CT, but does not require use of radiation. However, when these imaging modalities were compared in a randomized controlled trial they were found to have equivalent diagnostic accuracy within the emergency department. Both modalities have advantages and disadvantages. Kidney, ureter, bladder (KUB) plain film radiography is most helpful in evaluating for interval stone growth in patients with known stone disease, and is less useful in the setting of acute stones. MRI provides the possibility of 3D imaging without exposure to radiation, but it is costly and currently stones are difficult to visualize. Further developments are expected to enhance each imaging modality for the evaluation and treatment of kidney stones in the near future. A proposed algorithm for imaging patients with acute stones in light of the current guidelines and a randomized controlled trial could aid clinicians.