Advanced Therapy for Overactive Bladder Following Pelvic Organ Prolapse Surgery

Objectives: To determine the risk of developing overactive bladder (OAB) and progression to advanced OAB therapy following pelvic organ prolapse (POP) surgery.

Methods: This is a retrospective cohort study of a 100% fee-for-service sample of Medicare beneficiaries undergoing POP surgery from 2014-2015. Primary outcomes included a new OAB diagnosis and presence of a new advanced OAB therapy [i.e. onabotulinumtoxinA injections (BTX), sacral neuromodulation (SNM), or posterior tibial nerve stimulation (PTNS)] within 2 years of POP surgery. Demographic and case-based statistics were stratified by type of surgery (e.g. apical repair, anterior/posterior repair, apical with anterior/posterior repair, and obliterative approaches). Generalized linear regression models were used to calculate the relative risk for each of the primary outcomes. Independent variables included age, race, surgery type, concomitant hysterectomy, concomitant stress urinary incontinence (SUI) surgery, Charlson Comorbidity Index (CCI), Claims-Based Frailty Index (CFI), Area Deprivation Index (ADI), and pre-existing OAB diagnosis.

Results: Among the 68,020 beneficiaries analyzed, mean age with 73.9+/-5.8 years, 91.6% were White, and 4.5% had a pre-existing diagnosis of OAB. The majority underwent isolated anterior/posterior repairs (68.9%), followed by apical (15.5%), apical with anterior/posterior (9.6%), and obliterative approaches (6.0%). Fifteen percent had a new diagnosis of OAB. Age >=85 compared to 65-74 years (aRR 1.20, 95%CI 1.11-1.30), apical with anterior/posterior compared to obliterative approach (aRR 1/25, 95%CI 1.14-1.38), concomitant SUI surgery (aRR 1.32, 95%CI 1.27-1.36), CCI>=4 compared to 0 (aRR 1.54, 95%CI 1.42-1.67), and CFI>=0.25 compared to < 0.15 (aRR 1/65, 95%CI 1.53-1.79) were associated with greater risk of developing OAB.

Two percent of beneficiaries received new advanced therapy within 2 years of POP surgery. Type of prolapse surgery was associated with increased risk of undergoing advanced therapy, and apical repair demonstrated the highest risk compared to obliterative approach (aRR 1.68, 95%CI 1.22-2.11). Concomitant SUI surgery (aRR 1.55, 95%CI 1.39-1.73), pre-existing OAB (aRR 2.30, 95%CI 1.95-2.72), and CFI>=0.15 compared to < 0.15 (0.15<=CFI < 0.25 aRR 2.06, 95%CI 1.81-2.35; CFI>=0.25 aRR 3.89, 95%CI 3.16-4.81) were also associated with increased risk of advance therapies. Age>=85 compared to 65-74 years (aRR 0.74, 95% CI 0.56-0.97), non-White race (aRR 0.71, 95%CI 0.57-0.88), concomitant hysterectomy (aRR 0.46, 95%CI 0.39-0.53), and greater ADI (Q4 aRR 0.71, 95%CI 0.61-0.83, compared to Q1) were associated with lower risk of advanced therapies. The most common advanced therapy was SNM (41.2%), followed by PTNS (29.5%) and BTX (29.4%).

Conclusions: In a national cohort of female Medicare beneficiaries undergoing POP surgery, the incidence of OAB was fairly low at 15.0% and only a small precent progressed to advanced therapy within 2 years of surgery. The downstream implications of pelvic reconstructive surgery on lower urinary tract function may be minimal, yet perhaps advanced therapy should be considered earlier in the treatment paradigm of OAB in this population.