Introduction:

Microscopic hematuria (MH) is a common reason for urologic evaluation and is a frequent point of detection for urinary tract cancers, with an associated 2-4% risk of malignancy. National guidelines for the management and evaluation of MH have been in place many years, but adherence to previous guidelines has been poor. The AUA released updated guidelines in 2020 with a new risk-stratified approach for MH evaluation. These guidelines recommend shared decision-making for repeat urinalysis or cystoscopy and renal ultrasound for low-risk patients, cystoscopy and renal ultrasound for intermediate-risk patients, and cystoscopy and axial upper tract imaging for high-risk patients. Rates of concordance with contemporary guidelines among patients found to have MH is unknown. We aimed to describe current patterns of evaluation of patients with MH and assess concordance with current guidelines. We hypothesized that current medical practice would demonstrate better concordance with the new guidelines than with prior guideline iterations.

Methods:

We identified all patients presenting to our medical center with MH, based on presence of > 3 red blood cells per high-power field on a single microscopic urinalysis. Patients were excluded if they had prior diagnosis of a condition known to be associated with gross hematuria including urinary tract malignancy, nephrolithiasis, recent urinary tract infection, recent urologic procedures, and gross hematuria. Demographic and clinical information including age, sex, race, Elixhauser comorbidity index, smoking status, and date of MH diagnosis was abstracted from the electronic health record. MH evaluation performed for each patient, including use of repeat urinalysis, ultrasound, computed tomography, magnetic resonance imaging, and urology referral, was then obtained using EHR referral data and relevant CPT codes. Each patients’ risk group (low, intermediate, or high) was estimated with available data based on the 2020 MH guidelines. This study was approved by the Vanderbilt University Medical Center IRB.

Results:

There were 102,068 patients in the final cohort. Mean age was 49.6 years (SD 22), 65,898 (65%) were female. 77,712 (76%) were white, 16,110 (16%) black, and 5,468 (5%) Hispanic/Latino. Mean Elixhauser comorbidity index was 3.1 (SD 6.5). 17,724 (17%) identified as current smokers, 13,165 (13%) former smokers, and 52,107 (51%) never smokers. By current AUA guidelines, 15,339 (15%) were low risk, 18,465 (18%) intermediate risk, and 60,453 (59%) high risk. 23,439 (23%) of patients underwent CT imaging, 11,193 (11%) ultrasound, and 3,131 (3%) cystoscopy. 2,188 (2%) patients were ultimately referred to our urology department. On multivariable analysis, older age (p<0.001), male sex (p<0.001), black race (p=0.005), Elixhauser comorbidity index (p<0.001), and intermediate (p=0.017) or high-risk status (p=0.036) were significantly associated with likelihood of referral to urology and cystoscopy (all p<0.001). There were no significant temporal changes in rates of imaging, cystoscopy, or urology referral during the study period.

Conclusion:

In a large, single-institution cohort of patients diagnosed with MH without previously identified source, we found that adherence to current guidelines for MH evaluation and management remains quite low. Evaluation with appropriate imaging is uncommon and referral to urology is quite rare, even among high-risk individuals. Our study is limited by the single-institution population and claims-based dataset and strengths include large sample size. Despite these limitations, these data suggest that further work is needed to encourage guideline-concordant evaluation of patients with microscopic hematuria.

Funding: Vanderbilt Ingram Cancer Center Cancer Health Outcomes and Control Research Program Grant