P1156 Characteristics and outcomes of over a million Inflammatory Bowel Disease patients in seven countries: a multinational cohort study
Authors: Weisshof R , Magen-Rimon R , Voss E , Swerdel J , Sheahan A , Hall N , Park J , Park R W , Lee K J , Sung J S , Seo S I , Lee K J , Falconer T , Haas L , Nagy P , Bowring M , Cook M , Miller S , El-Hay T , Bivas-Benita M , Akiva P , Chowers Y , Yanover C 
Published: January 2024

Abstract

Background
Population-based studies are crucial for gaining insights into epidemiology, risk factors, and outcomes of IBD. However, studies that characterize patient cohorts typically analyze a single resource, apply diverse eligibility criteria, and extract different sets of attributes. This study aims to address this gap by employing a unified data and analysis framework developed by the Observational Health Data Sciences and Informatics (OHDSI) community to longitudinally describe and compare IBD patient cohorts across multiple geographic regions.

Methods
Using routinely collected healthcare data harmonized to the OMOP Common Data Model, we longitudinally characterized IBD patient cohorts across diverse geographic regions. Data sources included insurance claims and electronic health records from primary and tertiary settings. IBD cohorts were defined based on diagnoses and medications, and stratified into various groups (e.g. by sex and age at diagnosis).

Results
We characterized disease trajectory of 462,502 Crohn’s disease (CD) and 589,118 ulcerative colitis (UC) subjects, in 16 databases (DBs) from seven countries worldwide (table 1). There was a noticeable trend toward a decrease in the average age at CD diagnosis in Europe and North America (e.g., 47.5 in 2005-2010 period to 44.3 in 2020-2022 at a US DB) contrasting with more stable patterns in Southeast Asia (e.g., 33.7 to 33.9 respectively in Japan). A similar, though weaker, decrease in diagnosis age has been observed in UC subjects.
Prevalence rates of pre-diagnosis symptoms (abdominal pain, diarrhea, and rectal bleeding) were relatively stable over time, with minor differences between DBs. The proportion of females with anxiety was consistently higher across all datasets compared to males. Similarly, depression prevalence ranged between 11% to 46% in females and 0% to 33% in males.
Examining surgical outcomes for CD patients, our study uncovered nuanced trends. While there hasn't been a significant decrease in colonic resection rates within one year following diagnosis between the early 2000s and 2020 in US populations, some DBs demonstrated increased resection rates over time (from 11% in 2005 to 14% in 2020 and from 5% to 11% in two different US DBs). A similar trend was observed when examining the colonic resection rate 3 years post diagnosis. Small bowel resection rates were stable along time among most DBs one- and three-years following diagnosis.

Conclusion
This study, leveraging OHDSI network data and tools, provides a comprehensive characterization of IBD patient cohorts from various areas. It furnishes valuable insights into disease trends, demographic variations, outcome, and pre-diagnosis symptoms in CD and UC contributing to a deeper understanding of IBD epidemiology