Urinalysis Guidelines

Initial Evaluation and Follow-up

The American Urological Association recommends urinalysis for initial evaluation of suspected hematuria, and for asymptomatic microhematuria, yearly urinalyses should be conducted after initial negative workup, with no further evaluation necessary if two consecutive annual urinalyses are negative 1
Urinalysis helps determine the likelihood of UTI in febrile infants and young children (2-24 months) with no obvious source of infection, although a negative result does not completely rule out UTI 2

For children with suspected UTI, both urinalysis and urine culture are recommended, as urinalysis alone may miss 10-50% of culture-positive UTIs, with catheterization or suprapubic aspiration preferred for specimen collection in young children and infants 3, 2
Urine collected by bag specimen has high contamination rates (up to 85% false positives), making catheterization or suprapubic aspiration more reliable 3

Urinalysis is required prior to urologic interventions, particularly stone procedures, to screen for infection, with urine culture recommended if urinalysis suggests infection 4

Patients with gynecologic or non-malignant genitourinary conditions should have follow-up urinalysis after resolution to confirm resolution of hematuria, with anticoagulation therapy not changing the approach to hematuria evaluation 5
The American College of Physicians and the American Academy of Nephrology recommend obtaining a urine protein-to-creatinine ratio to quantify proteinuria and assess its severity 6, 7
The presence of 3-10 RBCs/HPF meets the criterion for microscopic hematuria, requiring comprehensive evaluation, according to the American College of Physicians and the American Academy of Family Physicians 8, 9
Repeat urinalysis is suggested to confirm persistence of hematuria and rule out transient causes, with consideration of autoimmune workup if glomerular disease is suspected 8, 10
Urine culture is recommended to rule out infection as a benign cause of microscopic hematuria 8

The American College of Physicians recommends considering referral to nephrology if proteinuria is persistent and greater than 500 mg/24 hours, or if hematuria is accompanied by proteinuria, suggesting glomerular disease 6
Evaluation for urologic malignancy is suggested if the patient has risk factors (age over 40 years, smoking history, or occupational exposures) and persistent hematuria after excluding benign causes 8
High-risk factors for urologic malignancy include age (women ≥50 years, men ≥40 years), smoking history >30 pack-years, gross hematuria or >25 RBC/HPF, history of pelvic radiation, chronic urinary infections, and occupational exposures 11, 12, 1

Imaging studies are recommended based on patient risk category, as follows:

Clinical Scenario	Recommended Imaging	Sensitivity	Specificity
Acute flank pain with hematuria	CT urography	92%	93%
Renal insufficiency or contrast allergy	MR urography or ultrasound	High	High
Young patients	Renal ultrasound	50%	95%

Proteinuria evaluation and management guidelines are as follows:
Proteinuria Level Management
>1,000 mg/24 hours Refer to nephrology
500-1,000 mg/24 hours Consider nephrology evaluation
<500 mg/24 hours Monitor periodically
9
Asymptomatic microhematuria (AMH) management guidelines are as follows: 1
Treatment of hematuria should be directed at the underlying cause, including antibiotics for infection, management of urolithiasis, and treatment of benign prostatic hyperplasia, as stated by the American Urological Association 1
Nephrology referral is warranted for consideration of renal biopsy to determine the histopathological diagnosis and guide therapy, as recommended by the American Academy of Clinical Infectious Diseases 7
Delays in evaluation of hematuria can be associated with decreased survival, emphasizing the importance of timely referral, as noted by the American College of Physicians 8
Shared decision-making with the patient is crucial in determining the need for further evaluation, as recommended by the American Urological Association 5

Proteinuria Level	Management
>1,000 mg/24 hours	Refer to nephrology
500-1,000 mg/24 hours	Consider nephrology evaluation
<500 mg/24 hours	Monitor periodically