Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS) is a condition defined by pain, pressure, or discomfort perceived to be associated with the bladder for a minimum of six weeks that is not explainable by infection or other cause. Definitive diagnosis of IC/BPS often can go unmade for up to 5 years. In women, the reported prevalence of IC/BPS ranges from 2.7-6.5% based on the definition applied. Patients with IC/BPS are reported to have a variety of related comorbid conditions, resulting in elevated healthcare resource utilization (HCRU) stemming from multiple caregivers and healthcare encounters. In this study, we aimed to characterize HCRU and healthcare costs in this population.

This was an observational, retrospective cohort study of patients with newly diagnosed IC/BPS and those without IC/BPS, utilizing real-world claims data from the Merative™ Marketscan® Commercial and Medicare Supplemental Databases between January 1, 2008, and December 31, 2022. Patients included in the IC/BPS group had at least one IC diagnosis (ICD-9-CM diagnosis code 595.1 or ICD-10-CM diagnosis code N30.1). Index date for patients with IC/BPS was defined as the date of first IC/BPS diagnosis between January 1, 2009, and December 31, 2021. To allow for a ≥12-month IC/BPS diagnosis-free baseline period prior to the index date and a ≥12-month follow-up period, patients were required to have at least 12 months of continuous enrollment prior to and after the index date. Patients included in the comparison (non-IC/BPS) group were required to not have an IC diagnosis during the entire study period and were randomly sampled and 1-to-1 exact matched with IC/BPS patients based on year of birth, sex, region, insurance type, and comparable follow-up time. Patients in both study groups were required to have birth year and sex information available and were excluded if they were on Healthcare Maintenance Organization (HMO) or Point of Service (POS) with capitation plan types. Patient demographics and clinical characteristics including comorbidities were assessed during the baseline period. HCRU and healthcare costs during the follow-up period were compared between patients in the IC/BPS and comparator groups. Additionally, we assessed clinical procedures during the baseline and follow-up periods for IC/BPS patients.

Patients in both the IC/BPS (N=65,853) and comparator groups (N=65,853) had a mean age of 48 years (standard deviation: 16.1); 90% were females, and majority (65%) had a Preferred Provider Organization (PPO) health insurance plan type. The matched comparator group composed of patients without IC/BPS had a similar mean age, proportion of females, and distribution of insurance type as the IC/BPS, as was expected given that patients were exact matched on those variables. Pain-related conditions were more than twice as likely to be present during baseline among IC/BPS patients compared to patients with no IC/BPS, with the most common being abdominal, back, or genital pain (59%), chronic pelvic pain (29%) and headaches (12%). Urinary tract infections were identified in 46% of IC/BPS patients compared to 7% in the comparator group. Similarly, among IC/BPS patients, other frequently identified baseline comorbidities included anxiety (17%), depression (16%), fibromyalgia (9%), migraines (9%), dyspepsia (7%), and irritable bowel syndrome (6%), all of which were more than twice as likely to occur in IC/BPS patients than the comparator group. 

Across the entire follow-up period, patients with IC/BPS experienced higher HCRU with an average total utilization of 20.6 visits per patient per year (PPPY) across all settings (inpatient [IP], emergency department [ED], and outpatient [OP]) compared to 11.3 visits PPPY in patients with no IC/BPS. This higher total HCRU in IC/BPS patients was driven by higher utilization of OP services among patients with IC/BPS (20.0 visits PPPY) compared to those without (11.0 visits PPPY). Similar results were observed when comparing OP and ED utilization. This trend of higher HCRU in the IC/BPS group was consistent across all time intervals during follow-up including the first, second, and third year of follow-up (Figure 1). 

Total healthcare costs during follow-up (including IP, ED, OP, and pharmacy costs) were about twice as high in patients with IC/BPS ($11,095 PPPY) compared to those without IC/BPS ($6,114 PPPY). As with HCRU, the higher total healthcare costs were driven by higher OP costs in patients with IC/BPS ($5,478 PPPY) compared to patients without IC/BPS ($2,949 PPPY). Similar differences were noted when comparing IP ($2,838 vs. $1,771 PPPY), ED ($795 vs. $364 PPPY) and pharmacy costs ($1,983 vs. $1,030 PPPY) between patients with and without IC/BPS, respectively. This trend of higher healthcare costs in the IC/BPS group was consistent across all time intervals during follow-up including the first, second, and third year of follow-up (Figure 2).

Among IC/BPS patients, the most frequent IC/BPS-related diagnostic procedures included post-void residual urine volume assessment by ultrasound (27% of patients), cystourethroscopy (23%), and computed tomography of abdomen and pelvis with contrast (19%). The most common therapeutic procedures included bladder instillation (23%) and cystourethroscopy with bladder dilation (17%).

This observational, retrospective cohort study using U.S. administrative claims data identified a higher baseline comorbidity burden in patients with newly diagnosed IC/BPS compared to matched patients without a diagnosis of IC/BPS. Specifically, the proportion of patients with IC/BPS with pain-related conditions, urinary tract infections, anxiety, depression, fibromyalgia, migraines, dyspepsia, and irritable bowel syndrome was at least two-fold higher. These results are consistent with findings from recent studies.(1, 2) Additionally, patients with IC/BPS were noted to have total HCRU and healthcare costs that were about twice that in patients without IC/BPS. This finding was consistent across all time intervals during the follow-up period. The higher total HCRU and costs in patients with IC/BPS were driven by higher utilization of OP services among patients with IC/BPS. These results are similar to findings from the Tung et al. study that also observed higher HCRU and healthcare costs among IC patients compared to non-IC patients during the 12-month follow-up period after IC diagnosis.(3)

This study found a higher comorbidity burden in patients with IC/BPS compared to matched patients without IC/BPS. Higher HCRU and healthcare costs were also noted in the IC/BPS group. The findings of this study highlight the complexities involved in the diagnosis of IC/BPS which appear to translate into higher HCRU and healthcare costs. Future work is needed to better understand the drivers of utilization and costs in this patient population.

Fischer-Grote L, Fossing V, Aigner M, Boeckle M, Fehrmann E. Comorbidities of bladder pain syndrome in the context of the HITOP distress category: a systematic review and meta-analysis. Int Urogynecol J. 2022;33(9):2335-56.
Laden BF, Bresee C, De Hoedt A, Dallas KB, Scharfenberg A, Saxena R, et al. Comorbidities in a Nationwide, Heterogenous Population of Veterans with Interstitial Cystitis/Bladder Pain Syndrome. Urology. 2021;156:37-43.
Tung A, Hepp Z, Bansal A, Devine EB. Characterizing Health Care Utilization, Direct Costs, and Comorbidities Associated with Interstitial Cystitis: A Retrospective Claims Analysis. J Manag Care Spec Pharm. 2017;23(4):474-482. doi:10.18553/jmcp.2017.23.4.474