Validity and reliability of a home-based, guardian-conducted video voiding test for voiding evaluation after hypospadias surgery

PURPOSE: To investigate the validity and reliability of a home-based, guardian-conducted video voiding test for assessing postoperative voiding function after hypospadias surgery. MATERIALS AND METHODS: In a single center, patients who had undergone urethroplasty by a single surgeon and postoperative uroflowmetry and video voiding tests conducted between 2008 and 2016 were retrospectively reviewed. Urinary stream was categorized into five grades by three pediatric urologists in a blinded manner. The primary outcome was statistical correlation across raters as measured by Spearman correlation coefficient to validate the interpretation of the video voiding test. The secondary outcome was the reliability of the voiding video test compared with maximum urinary flow rate assessed by uroflowmetry. RESULTS: Thirty-one patients with hypospadias were enrolled. The patients' average ages were 12.3±3.2 months (range, 8–21 months) and 42.8±3.9 months (range, 35–48 months) at the time of surgery and voiding video tests, respectively. Hypospadias was anterior, penile, and proximal in 1 (3.2%), 18 (58.1%), and 12 (38.7%) patients, respectively. The number of patients with each voiding stream grade was as follows: very poor, 4; poor, 4; fair, 13; good, 4; and very good, 6. All intraclass correlation coefficients of the stream grade among the three observers were >0.95. Correlation between the maximum flow rate obtained by use of conventional uroflowmetry and the video voiding stream grade was validated (rho 0.778, p<0.001). CONCLUSIONS: The home-based guardian-conducted video voiding test is easy to perform and the present results demonstrate its validity and reliability for assessing patients' post-urethroplasty voiding pattern.