Does physician specialty affect persistence to pharmacotherapy among patients with overactive bladder syndrome?

Introduction and Hypothesis: We compared persistence on overactive bladder (OAB) pharmacotherapy in patients treated in the Female Pelvic Medicine and Reconstructive Surgery (FPMRS) department compared with patients treated in the Internal Medicine (IM) and General Urology (GU) departments within an integrated health-care system. We hypothesized that persistence would be higher among FPMRS patients.
Methods: This was a retrospective cohort study. Patients with at least one prescription for OAB between January 2003 and July 2014 were identified. Demographic, prescription and treatment specialty data and data on the use of third-line therapies were collected. The primary outcome was persistence, defined as days on continuous pharmacotherapy. Discontinuation was defined as a treatment gap of ≥45 days. Discontinuation-free probabilities were calculated using the Kaplan-Meier method and compared among the specialties. Predictors of persistence were estimated using logistic regression with adjustment for covariates. Pearson correlation coefficients were calculated to identify risk associations.
Results: A total of 252 subjects were identified. At 12 weeks, 6 months and 1 year, FPMRS patients had the highest persistence rates of 93 %, 87 % and 79 % in contrast to 72 %, 68 % and 50 % in GU patients, and 83 %, 71 % and 63 % in IM patients (p = 0.006, p = 0.007, p = 0.001, respectively). The median persistence in FPMRS patients was 738 days, in GU patients 313 days and in IM patients 486 days (p = 0.006). Of the FPMRS patients, 61 % switched to at least a second medication, as compared to 27 % of IM patients and 14 % of GU patients (p < 0.0001).
Conclusions: Persistence on OAB pharmacotherapy was higher among FPMRS patients than among GU and IM patients in this community setting. These results suggest that persistence is higher under subspecialist supervision.