OR (95% CI) 4.0 (1.9, 8.3) 0.5 (0.3, 0.9) 1.0 (0.6, 1.6) 481 p value <0.01 0.02 0.86 <0.01 Int Urogynecol J (2011) 22:477–483 Table 2 Outcome measures comparing the 2 and 5 days protocol Protocol 2 days Protocol 5 days Percentage of patients needing temporary catheter replacement (n) Percentage of patients with a urinary tract infection at the time of first catheter removal (n)a Percentage of patients with uneventful postoperative periodb Hospital stay Median (range) 28% (35/123) 22% (22/101) 67% (82/123) 3.0 (2.0–42.0) 9% (11/122) 37% (35/95) 66% (80/122) 5.0 (1.0–59.0) a Urinary tract infection defined as culture with >105 colony forming unit per milliliter b Uneventful postoperative period defined as post-voiding residual <200 ml and no urinary tract infection (culture <105 colony forming unit per milliliter) at time of first catheter removal 200 mL needing catheter replacement with an odds ratio [OR] of 4.8 (95% confidence interval [CI] (2.3, 10.2); p < 0.01). This association was stronger in the 2-day protocol group compared with the 5-day protocol group (OR 12.4; 95% CI 4.1, 37.3; p < 0.01 versus OR 6.0; 95% CI 1.1, 31.6; p = 0.03). Table 4 shows the univariable and multivariable analyses of different variables to indicate whether they form risk factors for temporary indwelling catheter replacement. The multivariable analysis focused on risk factors for catheter replacement taking into account all significant factors in the univariable analysis. A urinary tract infection at the time of the first removal of the catheter and the protocol for catheterization itself appeared to be the only significant risk factors for temporary catheter replacement. Discussion The reason for prolonged drainage of urine by an indwelling catheter after an anterior repair is that postoperative edema of the bladder, or innervation trauma of the bladder, can cause voiding difficulties with increasing risk of retention. Overfilling of the bladder might possibly have a negative impact on the surgical outcome [2]. The question is how long postoperative catheterization should be continued. A Cochrane review focusing on catheterization of adults undergoing a uro- genital procedure was not able to draw conclusions on whether a catheter should be inserted after an anterior repair for a shorter or longer period postoperatively to prevent repeated catheterizations [7]. In our study, 28% of patients in the 2-day protocol needed repeated temporary catheterization compared to 9% of patients in the 5-day protocol (p < 0.01). These results are in line with a previous study, in which 40% of patients had retention after removing the catheter on the first postoper- ative day versus 9% of patients after removing the catheter on the fifth postoperative day [2]. To prevent one patient from needing repeated temporary catheterization, six patients in our study should have their catheter left in place for 5 days instead of 2 days. Giving a patient a catheter for 5 days instead of 2 days lengthened the hospital stay by 2 days, resulting in considerably higher hospital costs. This confirms findings by other investigators [7]. However, lengthening of hospital stay is probably not the result of the medical condition per se, but merely a result of the reluctance of many patients to leave the hospital with an indwelling catheter in situ and anxiety about removing the catheter by themselves. More patients underwent Kelly sutures in the 5-day protocol group compared to the 2-day protocol group. Kelly sutures, theoretically, can obstruct the urethra causing obstructive voiding with the risk of post-voiding residual volumes. If Kelly sutures had influenced the results of the study, they would have had a negative impact on the amount of catheter replacements in the 5-day protocol group. In Table 3 Urinary tract infections proven by a positive culture at the time of the first catheter removal Urinary tract infections in patients with post-voiding residual >200 ml Urinary tract infections in patients with post-voiding residual <200 ml Protocol 2 days Protocol 5 days Total group 16/30 (53%) 6/8 (75%) 22/38 (58%) 6/71 (8%) 29/87 (33%) 35/158 (22%) OR (95% CI), p value 12.4 (4.1, 37.3), <0.01 6.0 (1.1, 31.6), 0.03 4.8 (2.3, 10.2), <0.01