Bladder instillation patterns in a cohort of women with interstitial cystitis/bladder pain syndrome.

Purpose: To determine intravesical instillation patterns among women receiving treatment for interstitial cystitis/bladder pain syndrome (IC/BPS).

Methods: Using the Veterans Affairs Informatics and Computing Infrastructure, active female users of the Veterans Affairs system with an ICD-9 diagnosis of IC/BPS (595.1) were randomly sampled. Patients were considered to have IC/BPS (by chart review) if they had two visits complaining of bladder-centric pain in the absence of positive urine culture ≥6 weeks apart or history of bladder pain with one additional visit for bladder-centric pain. We abstracted the dates of intravesical instillations for each patient. A "course" of instillations was defined as ≥1 instillations made with <21 days between visits.

Results: We identified 641 women with confirmed diagnosis of IC/BPS, 78 of whom underwent a total of 344 intravesical instillations. On average each subject had 1.5 +/- 0.8 courses between October 2004-July 2016. Each course was an average of 3.1 +/- 2.6 instillations. 55% of courses consisted of one instillation. Only 22% of courses had 6 or more instillations, the number typically recommended to achieve clinical response. Each instillation within a course was an average of 9.4 +/- 4.0 days apart. Most instillations (77%) were a cocktail of two or more drugs.

Conclusions: In our cohort, few women with IC/BPS received a recommended treatment course of six weekly instillations, with most receiving only one per course. Future studies are needed to determine if instillation courses were altered from the guideline due to provider practice patterns, early improvement, or poor tolerance of instillations.