NEW YORK (Reuters Health) – An American Urological Association guideline — that heme-positive dipstick tests in asymptomatic patients be confirmed microscopically before urology referral – is often ignored, new research suggests.

The result is that many patients without true microhematuria undergo costly, unnecessary evaluations and testing, the researchers found.

According to the report in The Journal of Urology for February, microscopic urinalyses preceded urologic referral in just 37 (41%) of 91 asymptomatic patients with nonmacroscopic hematuria.

Moreover, only 22 of the 37 had microscopic findings should prompt referral, according to the guidelines: 3 or more red blood cells per high power field in 2 of 3 analyses.

“This establishes how frequent it is that patients are at risk of undergoing evaluation for findings that are actually not abnormal,” senior author Dr. J. Stephen Jones, from the Cleveland Clinic Foundation, told Reuters Health.

“Unfortunately, we were not surprised” by the findings, he added. “This is common and so we wanted to emphasize the importance of not making decisions based on the urine dipstick alone.”

The findings are from a study of 320 patients at the researchers’ center who had a diagnostic code of hematuria. This report focused on the 91 patients who were referred for asymptomatic nonmacroscopic hematuria.

Sixty-nine of the 91 patients did not have hematuria confirmed on microscopy before referral. At the urologist’s office, hematuria was confirmed in only 17 (25%) of these 69 patients. Of the 52 without true hematuria, 15 underwent imaging prior to referral.

The authors calculate that that the Medicare reimbursement value for the urologic evaluation of the 69 patients without microscopic confirmation before referral was $44,901. Thirty-five of these patients underwent cystoscopy, and just one (with true microhematuria) had a malignancy.

The take-home message for primary care physicians, Dr. Jones said, is not “to order invasive or radiological tests until determining whether there is true blood in the urine, but also never omit this important step of doing the microscopic exam.”

Reference:
J Urol 2010;183:560-565.