Barber et al (2008) compared the safety and effectiveness of the transobturator tape to TVT in the treatment of SUI in patients with and without concurrent pelvic organ prolapse. A total of 170 women were randomized to receive TVT or transobturator tape. Subjects with detrusor over-activity or previous sling surgery were excluded. The primary outcome was the presence or absence of abnormal bladder function, a composite outcome defined as the presence of any the following: incontinence symptoms of any type, a positive cough stress test, or re-treatment for SUI or post-operative urinary retention assessed 1 year following surgery. This study was a non-inferiority study design. Of 180 women who enrolled in the study, 170 underwent surgery and 168 returned for follow-up, with a mean follow-up of 18.2 +/- 6 months. Mean operating time, length of stay, and post-operative pain scores were similar between the 2 groups. Bladder perforations occurred more frequently in the TVT group (7 % compared with 0 %, p = 0.02); otherwise, the incidence of peri-operative complications was similar. Abnormal bladder function occurred in 46.6 % of TVT patients and 42.7 % of transobturator tape patients, with a mean absolute difference of 3.9 % favoring transobturator tape (95 % CI: -11.0 % to 18.6 %.). The "p" value for the 1-sided non-inferiority test was 0.006, indicating that transobturator tape was not inferior to TVT. The authors concluded that the transobturator tape is not inferior to TVT for the treatment of SUI and results in fewer bladder perforations. Moreover, they also noted that larger studies are needed to assess the relative risk of the less common but potentially severe complications that have been seen with both procedures. Furthermore, studies with longer follow-up are necessary to ascertain if the effectiveness of transobturator tape is durable.