Neurourology and Urodynamics 23:311^316 (2004) The Reproducibility of Urodynamic Findings in Healthy Female Volunteers: Results of Repeated Studies in the Same Setting and After Short-Term Follow-Up Amit Gupta, Gina Defreitas, and Gary E. Lemack* Department of Urology, UT Southwestern Medical Center, Dallas, Texas Aim: To assess the immediate (same testing period) and short-term (within 6 months) repeata- bility of urodynamic (UD) testing in asymptomatic healthy female volunteers. Materials and Methods: Twenty asymptomatic women with a mean age of 41.8 years (30^55) agreed to undergo a UD assessment which consisted of noninvasive uro£owmetry, post-void residual (PVR) measure- ment, medium-¢ll cystometry, and pressure £ow study with perineal surface electromyographic (EMG) electrodes. The UDS evaluation was repeated immediately without removing the catheters (a two-¢ll and void study). Sixteen women returned for an identical UD assessment 1^5 months later. Immediate and short-term repeatability of UD parameters was assessed by calculating the coe⁄cient of repeatability (COR). Results: The repeatability of certain parameters of immedi- ate UD testing could not be calculated since there was an apparent in£uence of the ¢rst test on the second (i.e., an apparent accommodation noted in bladder ¢lling volumes). Other immediate UD values (maximum £ow, detrusor pressure at maximum £ow, voided volume) had high COR values, as did all UD values on short-term testing, indicating relatively poor repeatability. Picking the ‘best’ pressure £ow value (highest £ow rate with accompanying detrusor pressure) did not consistently improve the COR values. Conclusions: The lack of repeatability of UD studies likely stems from a combination of the true physiological £uctuations in bladder function and the inherent relative insensitivity of our instruments in conducting these testing. Knowledge of the limitations of current technology is essential in allowing us to better utilize these studies in evaluating our patients and further improving diagnostic strategies. Neurourol. Urodynam. 23:311^316, 2004. ß 2004 Wiley-Liss, Inc. Key words: ¢lling cystometry; normal female voiding; pressure-£ow study; repeatability; reproducibility; urodynamics INTRODUCTION At present, multichannel urodynamic studies (UDS) com- prise the cornerstone for assessment of lower urinary tract dysfunction. While its utility has been questioned in some instances [Weber et al., 2002], there remains little else to sup- plantUDS in evaluating urinary incontinence and other types of voiding abnormalities. As a result, e¡orts have focused on standardizing the technique of UDS assessment [Schafer et al., 2002]. Since it remains an invasive procedure, and as such, may alter the primary goal of evaluation, which is to duplicate a patient’s symptoms without introducing artifact, there remains some question as to the accuracy of UDS measure- ments in certain scenarios [Groutz et al., 2000]. One way to evaluate the accuracy of a test is to determine its reproducibility over time given identical performance condi- tions. Considerable variability has been noted in pressure-£ow studies (PFS) conducted in men with lower urinary tract symptoms (LUTS) during the same study session, with up to 35% having their UDS diagnosis of obstruction change to equivocal or unobstructed on the second run [Sonke et al., 2000]. Others have noted the incidence of detrusor overac- tivity (DO) to be reduced on the second run of a repeated study, though consensus as to the e¡ect on measured bladder volumes (¢rst sensation of bladder ¢lling, ¢rst desire to void and maximum capacity) is lacking. It is unclear whether these di¡erences between studies re£ect inherent problems with the technology, or true changes in detrusor behavior [Kranse and van Mastrigt, 2003]. While a few researchers have investigated the long- term evolution of UDS ¢ndings in asymptomatic women [Sorensen et al., 1988], no data on the short-term reproduci- bility of UDS variables at di¡erent settings in this population has been published. Such information might provide insight not only into the reliability of UDS ¢ndings, but also, the inherent variability of detrusor behavior.We, therefore, asses- sed the reproducibility of UDS variables in studies performed *Correspondence to: Gary E. Lemack, 5323 Harry Hines Boulevard, Dallas, TX 75390-9110. E-mail: Gary.Lemack@utsouthwestern.edu Received 10 January 2004; Accepted 25 March 2004 Published online 24 May 2004 inWiley InterScience (www.interscience.wiley.com) DOI 10.1002/nau.20039 ß 2004Wiley-Liss,Inc.