Study finds widespread use of unregulated molecular urine tests in older adults

An analysis of Medicare claims data found a 60-fold increase in the use of unregulated rapid molecular diagnostic tests for urinary tract infections (UTIs) in older adults from 2016 to 2023, researchers reported Nov. 26 in JAMA Network Open.

For the study, researchers with the Centers for Disease Control and Prevention (CDC) used Centers for Medicare and Medicaid (CMS) claims data to assess the number and rate of paid claims for multiplex molecular syndromic panels for UTI among older Medicare beneficiaries.

Although urine culture is the traditional test for UTI, multiplex panels produce faster results, are more analytically sensitive, and can simultaneously detect multiple pathogens and some antibiotic-resistance genes.

While the Food and Drug Administration has approved multiplex molecular syndromic panels for bloodstream, respiratory, and other types of infections, it has not approved any such test for UTI diagnosis. However, the panels exist as laboratory-developed tests, and they can be used in labs certified under the Clinical Laboratory Improvement Amendments of 1988.

The researchers wanted to get a better understanding of how often these unregulated tests are being used, particularly in older adults, for whom UTIs are a common and leading reason for outpatient antibiotic use.

“Multiplex panels for UTIs are of particular interest for monitoring, given the large number of UTIs and the frequency with which antibiotics are given for asymptomatic bacteriuria, which may result in patient harm,” the study authors wrote.

Potential to increase inappropriate antibiotic prescribing

The study included more than 36 million older community-dwelling adults and nursing home residents with Medicare Part A and Part B benefits. Over the study period, researchers identified 1,679,328 claims for UTI multiplex testing. The median age of beneficiaries with claims was 77, and 66% of claims were from female beneficiaries.

From 2016 to 2023, the observed rate of UTI multiplex testing increased from 2.4 to 148.1 claims per 10,000 fee-for-service beneficiaries annually. The rate of urine cultures (1,116.2 claims/10,000 fee-for-service beneficiaries annually) did not increase over the same period.

The increase in UTI multiplex testing was most pronounced among beneficiaries residing in nursing homes, rising from 1% in 2016 to 12% in 2020. In addition to laboratories or pathologists, urology was the most common clinician specialty conducting this testing.

The study also found that the cost of UTI multiplex testing was 70 times higher than urine cultures, with a median cost per claim of $585 in 2023, compared with $8 for a urine culture.

The study authors say that while innovative diagnostics are needed to improve turnaround times and better differentiate asymptomatic bacteriuria from UTIs, the lack of specificity in UTI multiplex tests may lead to more antibiotic overprescribing. Furthermore, there is limited evidence demonstrating the benefit of UTI multiplex testing over urine culture.

“Clinicians should be aware of the lack of data supporting this testing and the potential to further contribute to inappropriate antibiotic prescribing,” they wrote. “Additional monitoring and research are needed to determine the effects of multiplex testing to diagnose UTI on antimicrobial use and whether there are clinical situations in which this testing may benefit patients.”

In an accompanying commentary, infectious disease experts from the University of Colorado School of Medicine and the University of Maryland School of Medicine say the findings raise concerns that the widespread and unregulated use of these tests will make a bad situation worse, particularly in settings such as nursing homes, where there is limited antimicrobial stewardship support.

“Inappropriate treatment of misdiagnosed UTI in patients with asymptomatic bacteriuria (ASB) is already a substantial problem, particularly among nursing home residents,” Margaret Fitzpatrick, MD, MS, and Daniel Morgan, MD, MS, wrote. “There is high potential for urine molecular tests to increase antibiotic overuse, causing increased antimicrobial resistance, adverse effects, and health care costs.”

They add that until data prove the clinical utility of multiplex UTI tests in various patient populations and care settings, CMS and other payers should consider not reimbursing for these tests, and medical societies should highlight the lack of evidence in UTI clinical guidelines.