Combining renal ultrasound and bladder cystoscopy is the most cost-effective approach for the initial evaluation of asymptomatic microscopic hematuria, even among patients at risk for genitourinary malignancy, according to a report published online April 17 in JAMA Internal Medicine.
“The superiority of this approach over the use of CT plus cystoscopy is driven primarily by higher costs of CT and the associated complications, albeit rare,” said Joshua A. Halpern, MD, of the department of urology, CornellUniversity, New York, and his associates. “Given the low prevalence of upper-tract malignant abnormalities in patients with asymptomatic microscopic hematuria, the small advantage in the sensitivity of CT imaging does not compensate for the significant additional costs.”
Every year, hundreds of thousands of patients undergo urinalysis for a variety of indications, and an estimated 40% are found to have microscopic hematuria in the absence of any urinary symptoms. This finding requires further evaluation because of one particular possible cause: a genitourinary malignancy. An estimated 11% of people with asymptomatic microscopic hematuria are found to have malignant abnormalities, the investigators said.
They assessed the cost-effectiveness of four common follow-up evaluations by creating a decision-analysis model to simulate the rates of cancer detection in adults with no history of cancer and with negative urine cultures that ruled out UTI as the cause of the hematuria.
The model was based on data from real-world experience in the medical literature and incorporated information on cancer incidence, diagnostic test accuracy, and complications.
The four approaches they examined were CT plus cystoscopy, which is considered the preferred method of diagnostic work-up by the American Urological Association; renal ultrasound plus cystoscopy, which many clinicians in the United States and other countries use instead; cystoscopy alone; and CT alone.
Compared with no follow-up evaluation, CT alone detected the fewest cancers (221 per 10,000 patients) at the highest cost ($9,300,000 per 10,000 patients). Cystoscopy alone detected 222 cancers per 10,000 at a cost of $10,287 per 10,000. Ultrasound plus cystoscopy detected 23 additional cancers per 10,000 patients at a relatively low cost of $53,810 per 10,000. Replacing ultrasound with CT detected just one additional cancer but cost an additional $6,480,484 per 10,000 patients.
The findings were similar in several sensitivity analyses, as well as in a subgroup analysis involving only higher-risk patients – men, smokers, and patients aged 50 years and older, the investigators noted (JAMA Intern Med. 2017 Apr 17. doi: 10.1001/jamaintenmed.2017.0739).
Dr. Halpern and his associates also applied their results to nationwide 2012 statistics for 485,222 patient visits to urologists to assess microscopic hematuria. If all urologists complied with AUA guidelines and used CT instead of ultrasound plus cystoscopy to assess these patients, they would have detected only 60 additional cancers, at an additional cost of $389,914,648.
Given these findings, renal ultrasound plus bladder cystoscopy should be considered the first-line assessment for these patients, Dr. Halpern and his associates said. Rewriting practice guidelines accordingly “will substantially reduce national expenditures associated with asymptomatic microscopic hematuria evaluation by up to $390 million.”
Moreover, recommending ultrasound rather than CT might have the unintended but beneficial consequence of improving compliance with further evaluation, because many primary care physicians are reluctant to refer these patients for radiocontrast CT studies, the researchers noted.
No sponsor was cited for this study. Dr. Halpern and his associates reported having no relevant financial disclosures.