Dipstick pseudohematuria: unnecessary consultation and evaluation

Abstract

Purpose: While many primary care providers advocate routine screening urinalyses, a heme positive dipstick test often leads to a false-positive diagnosis of hematuria, or pseudohematuria. Thus, American Urological Association guidelines recommend urological evaluation for asymptomatic patients only for at least 3 red blood cells per high power field in 2 of 3 microscopic urinalyses. We determined the percentage of patients referred for asymptomatic hematuria undergoing unnecessary consultation and studies.

Materials and methods: Patients were retrospectively identified if seen for initial consultation associated with CPT 599.7X, hematuria. Among these patients those referred for evaluation of asymptomatic nonmacroscopic hematuria were identified, and referral patterns, ancillary tests, procedures and findings were examined.

Results: Of 320 new patient visits with diagnosis code 599.7X, 91 were referred for asymptomatic, nonmacroscopic hematuria. Of these patients only 37 (41%) had microscopic urinalyses before referral and only 22 (24%) had microscopic urinalyses showing 3 or more red blood cells per high power field. Of the 69 patients referred without confirmed microhematuria approximately 25% had true microhematuria and 15 with no true hematuria had undergone imaging before referral. The Medicare reimbursement value for the evaluation of these 69 patients was $44,901. Of these patients 35 underwent cystoscopy and only 1 (with true microhematuria) had a malignancy.

Conclusions: Positive dipstick heme tests should always be confirmed by microscopic urinalysis before urological referral or evaluation. Education of referring physicians regarding the American Urological Association guidelines could possibly help limit costly and potentially harmful, unnecessary evaluation of patients without true microhematuria.