Screening and diagnosis

Classification and risk stratification

Perioperative care

Quality improvement

Patient education

Nonpharmacologic interventions

Therapeutic procedures

Respiratory support

Follow-up and surveillance

Specific circumstances

Preventative measures

Medical management

Surgical interventions

Inpatient care

Diagnostic procedures

Diagnostic investigations

Insufficient evidence to make a recommendation.

Strongly favor this test or intervention.

The diagnostic criteria for asymptomatic microhematuria are evaluated by considering two essential conditions related to urine analysis:

- The first condition is the presence of three or more red blood cells per high-power field (RBC/HPF) in a properly collected urinary specimen.
- The second condition involves the exclusion of any obvious benign causes for these red blood cells in the urine.

To determine if the diagnostic criteria are met, both conditions must be affirmatively selected by the user. Here's a breakdown of how the evaluation works:

- For Condition A (Presence of >= 3 RBC/HPF):
  - The user must confirm that the urinary specimen contains three or more red blood cells per high-power field. If this option is selected, Condition A is regarded as true.
  
- For Condition B (Exclusion of obvious benign cause):
  - The user needs to specify that no obvious benign cause accounts for the presence of red blood cells in the urine. If this option is selected, Condition B is considered true.

Both conditions need to be true for the diagnostic criteria to be satisfied. This means that if both the presence of red blood cells and the exclusion of benign causes are confirmed, the criteria for asymptomatic microhematuria are said to be met. If either or both conditions are not met, the criteria are deemed unmet. This structured approach ensures that the condition is accurately assessed based on the defined parameters.

The calculator in question is the Diagnostic Criteria for Asymptomatic Microhematuria. This is a clinical tool used to identify and evaluate patients who have asymptomatic microhematuria, which is the presence of red blood cells in the urine that is not visible to the naked eye and is not accompanied by any symptoms. 

The patient population for this calculator includes individuals who have had two or more positive results from urine dipstick or microscopic examination for red blood cells, without any accompanying symptoms such as pain or urinary tract infection. 

The clinical utility of this calculator is to guide clinicians in determining the need for further diagnostic testing, such as imaging or cystoscopy, to identify potential underlying causes of the microhematuria. These causes can range from benign conditions like urinary tract infections or kidney stones, to more serious conditions like bladder or kidney cancer. 

Exclusion criteria for the use of this calculator would include patients who have visible blood in their urine (gross hematuria), those with symptoms of a urinary tract infection, and those who have recently undergone a procedure that could cause blood in the urine, such as a biopsy or catheterization.

Diagnostic criteria for asymptomatic microhematuria

Microhematuria

Risk stratification

Initial evaluation

Urine cytology

Initial imaging and cystoscopy

Repeat urinalysis

The American Urological Association (AUA) has updated its guidelines for the evaluation of microhematuria. Changes include modifications to age groups used in risk categorization and reclassification based on repeat urinalysis. Repeat urinalysis in 6 months is recommended for low/negligible-risk patients, while cystoscopy and renal ultrasound are recommended for intermediate-risk patients. Upper tract imaging is recommended for patients with a family history of renal cell carcinoma, a known genetic renal tumor syndrome, or a personal or family history of or suspicion for Lynch syndrome, regardless of risk category. Urine cytology is suggested in certain cases, such as high-risk patients with equivocal findings or persistent microhematuria with irritative symptoms.


Microhematuria

Guidelines

Key sources