News Release

Wednesday, May 2, 2012

Bladder tests before urinary incontinence surgery in women may be unnecessary

NIH-funded study finds pre-operative office visit alone sufficient for comparable outcomes.

An invasive and costly test commonly done in women before surgery for stress urinary incontinence may not be necessary, according to a study funded by the National Institutes of Health. The study compared results after both a pre-operative check-up in a doctor's office and bladder function tests to results after only the office check-up. Women who had only the office check-up had equally successful outcomes after surgery.

Results of the study, done by researchers in the Urinary Incontinence Treatment Network (UITN), are posted on the New England Journal of Medicine's website and will be in the journal's May 24 print issue.

Urinary incontinence is conservatively estimated to affect 13 million Americans, most of them women. Stress urinary incontinence occurs when the bladder leaks urine when a person coughs, laughs, sneezes or exercises. The stress refers to pressure on the bladder, not emotional stress. Strong pelvic and sphincter muscles can handle the extra pressure from a cough or other sources of stress, but when these muscles are weak, sudden pressure can push urine out of the bladder. Among other causes, childbirth can injure or weaken the nerves, muscles and structures that help support the bladder in women.

“Bladder function tests are often performed before surgery in women who demonstrate stress incontinence upon office evaluation,” said study lead author Charles Nager, M.D., director of urogynecology and reconstructive pelvic surgery at the University of California, San Diego. “The findings of our study argue against routine pre-operative testing in cases of uncomplicated stress urinary incontinence, as the tests provide no added benefit for surgical treatment success but are expensive, uncomfortable, and may result in complications such as urinary tract infections.”

Called urodynamic studies, bladder function tests help assess how well the bladder, sphincter muscles, and urethra — the tube that carries urine from the bladder to outside the body — store and release urine. Since some of the tests involve the insertion of catheters and filling the bladder until full, many women find them uncomfortable or, in some cases, painful. The average cost is roughly $500.

The multi-center clinical trial tested the benefits of urodynamics to improve outcomes one year after surgery for predominantly stress urinary incontinence. Treatment success was defined as a patient reporting on a questionnaire that her urinary distress had been reduced by 70 percent or more, as well as reporting that her urinary tract condition had improved “much” or “very much.”

In the study, half of 630 women with uncomplicated stress urinary incontinence had a pre-operative office check-up and bladder function testing. The other half had only an office check-up. Treatment success was similar in both groups, 76.9 percent versus 77.2 percent respectively, with no significant differences in quality of life, patient satisfaction, or voiding dysfunction — an inability to empty the bladder completely.

The UITN is a group of NIH-funded U.S. urologists and urogynecologists who research treatments for urinary incontinence. Learn more about the UITN at and incontinence at

The UITN study was supported by the NIDDK and the Eunice Kennedy Schriver National Institute of Child Health and Human Development (NICHD), both components of the NIH. For more information on the study, visit and enter keyword NCT00803959.

The NIDDK, a component of the NIH, conducts and supports research on diabetes and other endocrine and metabolic diseases; digestive diseases, nutrition and obesity; and kidney, urologic and hematologic diseases. Spanning the full spectrum of medicine and afflicting people of all ages and ethnic groups, these diseases encompass some of the most common, severe and disabling conditions affecting Americans. For more information about the NIDDK and its programs, see

About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit

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