NGF and overactive bladder: In addition, there was a significant difference between patients with IC/PBS and patients with overactive bladder (OAB) symptoms with respect to the urinary NGF and NGF/Cr levels (SMD = −0.62, 95%CI = −1.00–−0.24, P = 0.001 and SMD = −0.70, 95%CI = −1.01–−0.39, P<0.0001, respectively).