Urinary Incontinence Diagnostics

Laboratory Tests and Ancillaries

Initial Assessment in Women  

Diagnostic Exams  

A urine dipstick test and urinalysis with or without urine culture and sensitivity can be done, and urine cytology, if hematuria or pelvic pain is present. HbA1c may also be done. Request serum creatinine and blood urea nitrogen (BUN) to check for renal function.  

Cough Stress Test  

Patients who have not recently voided urine may be asked to stand over a pad, and then they should cough vigorously. Observe if there is leakage of urine on the pad. An abrupt leakage gives a diagnosis of stress incontinence while delayed leakage suggests mixed incontinence.  

Post-Void Residual Volume (PVRV)  

Post-void residual volume should be considered if the patient has symptoms of voiding dysfunction or a history of recurrent UTI, previous anti-incontinence surgery, significant pelvic prolapse or spinal cord injury. This should also be used to monitor patients on therapy that may cause or worsen voiding dysfunction. Catheterization is the most accurate method, but ultrasound may be preferred due to higher patient acceptability, avoidance of infection and lower incidence of adverse events from the procedure. A PVRV <50 mL is considered adequate emptying while a PVRV >200 mL is inadequate. A PVRV that is persistently >150 mL warrants further evaluation.  

Urodynamics  

Urodynamics should only be considered in women with symptoms of complicated or refractory UI. It aids in providing or confirming a diagnosis of UI if there are conflicting history and physical examination findings. This is often done before invasive treatment for UI. Urodynamics should be performed if the results may affect the choice of invasive treatment. Multichannel filling and voiding cystometry should not be done prior to primary surgery if the patient is diagnosed with stress UI or stress-predominant mixed UI.

Referral  

Specialist referral should be considered in a patient with a complex history (eg recurrent incontinence or incontinence associated with hematuria, pain, recurrent UTIs, suspected fistula, pelvic surgery or radiotherapy, pelvic organ prolapses, and/or voiding symptoms).

Initial Assessment in Men  

Diagnostic Exams  

Urinalysis with or without urine culture should be part of the initial assessment. If infection is found, treat and then reassess.  

Post-Void Residual (PVR) Volume  

Post-void residual volume measures the amount of urine that remains in the bladder after voiding. It indicates poor voiding efficiency and should be part of the initial assessment in the male patient as its presence is associated with UI symptoms. Catheterization is most accurate, but ultrasound may be preferred to avoid infection risk and it has higher patient acceptability. The presence of voiding dysfunction is considered in patients with persistent PVR >100 mL.  

Flow Rate  

Flow rate may be determined by detailed clinical history.  

Pad Testing  

Pad testing is done by using an absorbent pad worn over a period of time or during a protocol of physical exercise where urine loss is measured. It can be used to quantify the presence and severity of UI and also to assess the patient’s response to treatment.  

Referral  

Specialist referral should be considered in a patient with a complex history (eg recurrent incontinence or incontinence associated with hematuria, pain, recurrent UTIs, prostate irradiation, pelvic surgery or radiotherapy, and/or voiding symptoms).

Imaging

Assessment with renal ultrasound to exclude hydronephrosis or hydroureter in women with advanced pelvic organ prolapse. Voiding cystogram may be done to check for stress incontinence, cystocele and degree of urethral motion. Perform an intravenous pyelogram to rule out developmental abnormalities, tract anomalies and the presence of fistula.  

Cystoscopy should be done in women with gross hematuria or complicated UI and may also be indicated in those with symptoms of refractory UI, iatrogenic genitourinary fistulas or injuries and persistent post-void dribbling. In the evaluation of women with uncomplicated stress incontinence, imaging studies of the upper or lower urinary tract should not be routinely done.