Nearly 90% of preoperative urine tests are not indicated, study finds

Unnecessary preoperative testing is a significant source of overuse, and can lead to harmful and costly care cascades. For example, one 2019 study found that 16% of Medicare patients who received a preoperative electrocardiogram before cataract surgery experienced a cascade event within 90 days, such as another cardiac test, a cardiac specialist visit, and cardiac treatment.

Tests for urinary tract infections (UTIs) before procedures are common, even though there is no evidence that the tests reduce the risk of infectious complications after surgery. In fact, these tests can cause serious harm. If bacteria are found in the urine, antibiotics are commonly prescribed, which can lead to adverse drug reactions, C.diff infections, and increases the future risk of antibiotic resistance. That’s why specialty groups like the Infectious Diseases Society of America, the US Preventive Services Task Force, and the American Society of Anesthesiologists Task Force recommend against urine testing before most procedures unless UTI symptoms are present.

Between 5.8% and 28% of patients who had an unnecessary preoperative urine test later received an antibiotic prescription, depending on the procedure.

In a recent study in JAMA Internal Medicine, researchers at the Harvard Medical School looked at ten year’s worth of medical claims, to find out how often preprocedure urine tests occurred for 14 common procedures. Overall, 25% of patients that had these procedures had a urine test within 30 days. However, the rate varied by procedure. For example, 40% of patients had a urine test before a joint replacement, while just over 10% had a test before an orthopedic trauma procedure.

The researchers also examined how often these preoperative urine tests were indicated by patient’s conditions or symptoms. If patients had bladder or urethra inflammation, fever, painful urination, altered mental status, or other urinary symptoms, the test was considered indicated. However, 89% of the urine tests done before procedures were not indicated by any of these diagnoses, the researchers found (ranging from 84% to 94% across procedure categories). For patients that received a urine test, between 5.8% and 28% later received an antibiotic prescription, depending on the procedure.

The researchers uncovered trends related to preoperative urine tests as well. Out of the 14 procedures studied, joint replacement procedures, prostate surgery, and spine surgery had the highest rates of non-indicated urine tests. There was also an intriguing finding around health plan type: Among Medicare beneficiaries that received urine tests, 37.2% had Medicare Advantage, compared to 19.1% of beneficiaries that did not receive a test. This could be an example of Medicare Advantage providers testing more to increase the number of diagnoses per patient, which increases their reimbursement.

“Medicare Advantage plans have a financial incentive to ensure that their providers record all possible diagnoses, since higher enrollee risk scores result in higher payments to the plan.”

Ken Terry and David Muhlestein, Health Affairs

In an accompanying editorial in JAMA Internal Medicine, Chief Resident at Beth Israel Deaconess Hospital Dr. Niloofar Latifi and JAMA-IM Deputy Editor Dr. Deborah Grady suggest policies to reduce preoperative urine testing. One fairly simple solution — Medicare and commercial insurers should stop paying for these tests, unless they are indicated by specific diagnoses. “Payment policy changes that eliminate reimbursements for low-value services have shown a marked association with reducing unnecessary services,” Latifi and Grady write.

Institutional policies like “diagnostic stewardship” programs, clinician education, and third party oversight are other ways to reduce low-value diagnostic testing. However, the authors note that education alone is not enough to stop unnecessary testing — there must be incentives or accountability for following through.

Lastly, measuring what matters is key for holding health care institutions accountable. The Lown Institute Hospitals Index evaluates hospital overuse of 12 common low-value services, including diagnostic tests — perhaps a metric for preoperative urine testing is next on the horizon.