(36) Treatment Patterns for Inflammatory Bowel Disease in Japan and The US (2010-2019)

Publication Number: 367

Background: Variations in treatment patterns (RxP) of inflammatory bowel disease (IBD) reflect different disease (Dx) trends and clinical practices. Guidelines (GLs) for the management of IBD recommend considering extent, severity, and current activity of the Dx in deciding Rx, although GLs in Japan (JPN) do not specify a Rx target.

Objectives: To summarize RxP among patients (pts) with IBD (Crohn’s disease [CD], ulcerative colitis [UC]) in JPN and the US.

Methods: A retrospective cohort study using 2 claims databases (DBs), Japan Medical Data Center (JMDC) and IBM Commercial Claims and Encounters (CCAE), described IBD RxP with the study period (SP) 2010-2019. Pts with incident IBD were included, who never had IBD diagnosis prior to index date (ID: the 1st IBD diagnosis during SP) among those continuously insured ≥6 months (mo) prior to ID, with ≥12 mo follow-up.
Characteristics of IBD Rx were described, including time (T: days) from ID to 1st IBD Rx, IBD polypharmacy (PP: multiple IBD Rxs overlapping ≥60 days based solely on days supply), T 1st IBD Rx persisted, %1st IBD Rx persisted ≥12mo, T from Day 1 of 1st Rx to discontinuation (discont’), %1st Rx discontinued (discont'ed: >45 days gap between Day 1 of 1st IBD Rx and last day insured, based on last Rx claim, days supply, and buffer window), and IBD Rx switch occurring before 1st Rx discont’.

Results: 83,208 pts in CCAE (42% CD, 58% UC) and 8,096 pts in JMDC (15%, 85%) were included in the analysis, who were ever treated for IBD (2010-2019), including biologic users [18,600 (11,723 CD, 6,877 UC) and 913 (445 CD, 468 UC), respectively]. Mean age (yrs) and %females were 37.9 and 55 [CD] and 41.9 and 55 [UC] in CCAE, and 33.1 and 26 [CD] and 39.6 and 35 [UC] in JMDC. Over 90% of pts started with a single Rx of 5-ASA or corticosteroid (CS) in both DBs. (Results are presented hereafter as CCAE vs JMDC.)
First IBD Rx initiated on ID (%): 34 vs 51 [CD] and 49 vs 61 [UC] (both p< 0.0001). %1st IBD PP occurred among pts receiving 5-ASA: 53 vs 94 [CD] and 78 vs 91 [UC] (both p< 0.0001). Median T from 1st IBD Rx to 1st IBD PP: 119 vs 85 [CD] and 162 vs 78 [UC] (both p< 0.0001). Median T 1st IBD Rx persisted: 104 vs 227 [CD] and 90 vs 254 [UC] (both p< 0.0001). %1st Rx persisted ≥12mo: 31 vs 45 [CD] and 26 vs 46 [UC] (both p< 0.0001). Median T from 1st Rx to discont’: 77 vs 36 [CD] (p < 0.0001) and 69 vs 77 [UC] (p=0.0119). %1st Rx discont’ed: 88 vs 67 [CD] and 90 vs 68 [UC] (both p< 0.0001). Most frequent switching occurred (%): 5-ASA to CS (16 vs 24 [CD] and 21 vs 59 [UC]) and CS to 5-ASA (26 vs 8 [CD] and 46 vs 16 [UC]) (all p< 0.0001).

Conclusions: More pts started 1st IBD Rx on ID, 1st IBD PP occurred sooner, and pts stayed on 1st IBD Rx for a longer period in JPN. More 1st IBD Rx was discont’ed while pts were continuously insured in the US. GLs appeared playing role in different RxP observed in 2 populations with employment-based insurance.