Background: IBD Qorus is a multicenter adult IBD learning health system which has worked to reduce unnecessary ED and hospital utilization via a recent urgent care improvement initiative. Building upon initial work by Almario et al. (2021) using Markov modeling to estimate pre-post cost differences related to ED visits and hospitalizations with the improvement initiative, and real-time monitoring adaptation by Oliver et al. (2023) using Statistical Process Control, we estimated overall, ambulatory, and inpatient costs of care for Qorus using claims data before and after the improvement initiative implementation.
Methods: A retrospective, observational cohort study was conducted of individuals enrolled in IBD Qorus between 2/1/2018 and 6/30/2019, encompassing 5-month windows prior to and after the improvement initiative. Improvement efforts were conducted among 24 clinical sites. Each site implemented practice modifications derived from a pool of change ideas developed by IBD Qorus.
Eligible individuals in IBD Qorus were identified in the Healthcare Integrated Research Database (HIRD), which contains administrative claims and enrollment information for a large commercially insured US population. Eligible individuals were ≥18 years of age and were enrolled in commercial or managed Medicare plans. Demographics including age, sex, insurance type, and geographic region were described for the full study cohort and stratified by IBD subtype (Crohn’s disease (CD) vs Ulcerative colitis (UC)). Unadjusted median costs for healthcare utilization outcomes of interest were calculated for the baseline and post-program period, including all-cause and IBD-specific inpatient hospitalizations, ER visits, outpatient medical visits, and pharmacy costs. Costs were defined as total patient-paid and plan-paid amounts. All costs were inflated to 2022 values and presented as per-patient per-month averages. Mean enrollment time was reported.
Results: In the linked IBD Qorus and HIRD environment, 177 individuals met inclusion criteria (103 CD, 69 UC). The median (IQR) age was 40 years (29-54), and 51% of the cohort was male. Most individuals (97%) were commercially insured (Table 1). Total all-cause and IBD-specific costs were similar during the pre-program and post-program time windows (Table 2). While there were modest increases in average per-patient per month expenses in the outpatient setting, there were relatively large reductions in both all-cause and IBD-related costs related to hospitalizations among patients requiring inpatient care.
Conclusions: In this cohort, overall costs of all-cause and IBD-related care remained stable before and after the IBD Qorus Improvement initiative, though there were large reductions in costs related to hospitalizations. Future analyses adjusting for disease characteristics and severity would serve to better validate these findings.

Table 1: Cohort characteristics of IBD Qorus and HIRD overlap population
Abbreviations: UC = Ulcerative Colitis, CD = Crohn’s Disease, SD = Standard Deviation
1Medicare Other includes Medicare Supplement & Part D
2Pre-program period is 2/1/2018-6/30/2018
3Post-program period is 12/1/2018-4/30/2019

Table 2: All cause and IBD-specific costs, presented as mean(SD) and median(IQR). All costs are presented in 2022 USD, and are per-patient, per-month averages.
*IBD-related visits (inpatient, ER, and outpatient) identified using claims with IBD diagnosis (ICD-10-CM) or IBD-related medication (HCPCS) codes. IBD-related pharmacy fills identified using IBD-related NDC/GPI medication codes.
1Sum of plan paid, patient paid, and coordination of benefits (payments made by a third party) amounts.
2Calculations based on inpatient costs for those with ≥1 inpatient stay; they are not standardized to the monthly level.
3Including office visits, procedures, imaging, laboratory tests, durable medical equipment, medication services, physical therapy, and other outpatient services
4Total outpatient medication costs are the sum of drug spending accrued under either outpatient medical or outpatient pharmacy benefit