Hypothesis / aims of study
Patients with overactive bladder syndrome (OAB) are treated according to a stepwise approach, with conservative treatments followed by more invasive ones (1). Since the efficacy of each step differs in patients and outcomes are poorly predictable, this approach often is time-consuming and disappointing from a patients’ perspective. The aim of this study was to map the OAB-patient’s pathway in a large teaching hospital. First, we evaluated the effect and duration of each of the offered OAB treatments. Second, we questioned if derogation from the guideline affected treatment duration? Third, we tried to identify case-mix variables as predictors for treatment duration.
Study design, materials and methods
This study is retrospective cohort study of all female patients with idiopathic OAB that visited the outpatient clinic of a large teaching hospital. A search was done, using the search engine Ctcue, in the electronic patient records (EPR) of patients treated for OAB or urgency incontinence between January first 2014 and September the 30th of 2016, allowing a follow-up period of at least one year. Patients younger than 18 years or women with OAB symptoms due to neurologic disorder, bladder tumor, bladder stones, urinary tract infection or interstitial cystitis were excluded from the analyses.
OAB-treatment modalities provided in our hospital were pelvic floor muscle therapy (PFMT), anticholinergic drugs, alternative anticholinergic drugs, mirabegron, percutaneous tibial nerve stimulation (PTNS), intravesical injections with Onabotulinum Toxin A (Botox®) and sacral neuromodulation (SNM). All data were retrieved from the medical files, using a structured case report form, and entered in Research Manager.
Duration of the treatment was defined by the number of days from the first to the last visit in our outpatient clinic per treatment modality. Treatment succes was defined as patient satisfaction and no need to start a new treatment. A survival analysis was done comparing patients that were treated according to the guideline with patients that were not treated according to the guideline. Case-mix variables that might affect OAB treatment outcomes as defined by the International Consortium for Health Outcome Measurement (ICHOM) were included in the analyses to allow for risk adjusted outcome comparisons (2). These variables were age, body mass index, bowel disease, diabetes, cognitive impairment, pelvic organ prolapse, stress urinary incontinence, current use of estrogens and history of pelvic surgery. Case-mix variables were analyzed using the Cox proportional hazards model for their predictive value of treatment duration.
Statistical analysis was performed using IBM SPSS Statistics 24.0.
Of 296 patients found with Ctcue, 119 patients met inclusion criteria, of which 81% reported urgency incontinence. Fourty-four percent of patients were treated according to the guidelines. About half of all women underwent PFMT, of which 35 were classified as successful. About two-thirds of women received an anticholinergic drug (with 25% effect), and a small number received a second anticholinergic, whereas 15% of patients mirabegron was prescribed as second option after initial anticholinergic therapy. A total of 39 women received mirabegon, as first, second or third step, showing around 30% effect. Of these patients, 22% did not receive an alternative anticholinergic. PTNS was offered to 36% of patients, where in 6% PTNS was started before medication, mostly because of patient’s preference. Mean age was 59.1(16.1) years. Prevalence of BMI>25 was 66%. Thirty seven percent of patients had bowel disease. Patients with pelvic organ prolapse were 33% and 47% of patients had previous pelvic surgery. None of the case-mix variables, as analyzed with Cox proportional hazards model, were predictive for treatment duration.
Interpretation of results
This study shows that the OAB-patient’s pathway is not an easy one. Especially conservative treatments have poor efficacy and are time-consuming. We found no difference in treatment duration in relation to adherence to the guideline, and were unable to predict treatment duration by case-mix variables. Further research should aim at patient’s expectations and experiences of the current stepwise approach, in order to optimize the OAB-treatment pathway to the patient’s needs.