Use of symptom-relieving drugs before and after surgery for urinary incontinence in women: A cohort study

Abstract

Drugs (antimuscarinic drugs or duloxetine) before and after surgery for urinary incontinence (UI); and for those with use of antimuscarinic drugs or duloxetine before surgery, to estimate the risk of being a postoperative user, relative to those without use before surgery. Design: A historical population-based cohort study. Setting: Denmark. Participants: Women ≥18 years with a first-time surgical procedure for UI from the county of Funen, Denmark between 1 January 1996 and 31 December 2006, extended to the Region of Southern Denmark from 1 January 2007 to the end of 2010. For these women, data on redeemed prescriptions ±365 days of date of surgery were extracted. Main outcome measures: Effect of preoperative use of antimuscarinic drugs or duloxetine on the risk of being a postoperative user of these drugs. Results: Of 2151 women with a first-time surgical procedure for UI, 358 (16.6%) were preoperative users of antimuscarinic drugs or duloxetine and 1793 were not (83.4%). A total of 110 (30.7%) of the preoperative users also redeemed prescriptions for these drugs within 0-60 days after surgery, and 152 (42.5%) of the preoperative users redeemed prescriptions for these drugs within 61-365 days after surgery. Among preoperative non-users, 25 (1.4%) and 145 (8.1%) redeemed prescriptions within 0-60 and 61-365 days after surgery, respectively. Presurgery exposure to antimuscarinic drugs or duloxetine was a strong risk factor of postoperative drug use, both within 0-60 days (adjusted OR=33.0, 95% CI 20.0 to 54.7) and 61-365 days (OR=7.2, 95% CI 5.4 to 9.6). Conclusions: A substantial number of women will continue to be prescribed symptom-relieving drugs after surgery for UI within a year of follow-up. Only a minority of preoperative non-users initiated usage of symptomrelieving drugs after surgery. Compared with other factors included in the regression model, preoperative use of antimuscarinic drugs or duloxetine was the strongest risk factor for postoperative use.