Introduction: Intravesical onabotulinumtoxinA is a third-line therapy option for treatment of overactive bladder (OAB), with an average response of 6 months, sustained over 36 months, based on initial trials. However, these studies did not address increases in onabotulinumtoxinA dose over time for progression of disease. The objective of this study was to determine patient factors that are associated with increased onabotulinumtoxinA dose over time. Methods: After IRB approval, a retrospective chart review was performed of all patients who received onabotulinumtoxinA treatments in a female pelvic medicine and reconstructive urology practice between January 2010 and July 2021. Patients were identified using CPT procedure code 52287 and data was extracted. Data reviewed included age, gender, race, BMI, smoking history, type of incontinence, surgical history, menopausal status, hormone replacement therapy use, number and dose of onabotulinumtoxinA treatments, time between treatments, and prior OAB therapies (type of medication, neuromodulation). Outcomes measured included duration of response and a dose escalation at the second or third onabotulinumtoxinA injection. Univariate comparisons were performed with the chi-square test and T-Test for categorical and continuous variables. Multivariate analysis was performed with logistic regression modeling. Results: A total of 209 patients received intravesical onabotulinumtoxinA injections during the study. Mean age was 73 years. 147 (70.3%) patients underwent more than one treatment. 46 (22.0%) patients were found to have 0-6 months between the first and second treatments, 58 (27.8%) patients had 6-12 months between treatments, and 45 (21.5%) patients had over 12 months between treatments. There were no significant associations between any factors and response time; however, patient age less than 60 (56.2% vs. 26.0%, p=0.01) and dual medical therapy (35.7% vs 22.5%, p=0.04) were both associated with a dose escalation. Both factors remained significant under multivariable analysis. Conclusions: In our cohort, patients who were younger or receiving dual medical therapy were significantly more likely to have their onabotulinumtoxinA dose increased. Over the course of treatment, no significant difference was found in patient response in the setting of increasing doses. Thus, increased dosage of onabotulinumtoxinA did not directly correlate with response. This information can be used when counseling patients as to post-procedure expectations. SOURCE OF Funding: None
