Title: Prevalence and Trends of Inflammatory Bowel Disease (IBD) in the Israeli Population
Authors: Prof. Dan Turner and Ms. Mira Friedman The Institute of Pediatric Gastroenterology, Guelitte Kaidan Children's Hospital Shaare Zedek Medical Center, Jerusalem
Background:
This research was conducted under the leadership of Shaare Zedek Medical Center in collaboration with four health funds and six other hospitals (Ichilov, Tel Hashomer, Rambam, Soroka, Beilinson, and Hadassah), and with funding from the Lemselie Foundation. Initially, computer algorithms were developed and implemented to accurately identify patients with IBD from the health fund databases, as well as to determine the estimated date of diagnosis in a two-year process. The algorithms applied to the data integrated diagnostic codes, duration of specific medication use for IBD, and the number of purchases of these medications. This approach enabled the identification of true patients with IBD from the entire population (87% sensitivity, 95% specificity, 90% positive predictive value, and 93% negative predictive value - using data from all four health funds), particularly to distinguish insured individuals with at least one IBD diagnostic code who are not actually patients (approximately 40% false positives).
Disease Types - Crohn's vs. Ulcerative Colitis: The disease type - Crohn's disease versus ulcerative colitis - was determined using the majority diagnosis from the three most recent diagnoses, or the latest diagnosis in cases of fewer than three diagnoses (sensitivity - 93%, specificity - 94%, positive predictive value - 94%, negative predictive value - 94%).
Presence of IBD in the Population: As of December 31, 2015, there were 38,291 individuals living with IBD in Israel. This translates to 453 patients per 100,000 residents, or 0.456% of the population (considering 8,463,400 Israeli residents at that time). Of these, 20,196 (53%) had Crohn's disease and 17,810 (47%) had ulcerative colitis; their rates in the population were 244 and 215 per 100,000 residents, respectively. 285 (0.8%) had a general IBD diagnosis not assigned to a specific category. In Israel, there were 1,497 children up to the age of 18 with IBD, with a higher disease rate for Crohn's disease than ulcerative colitis in this age group (65% vs. 35%). Figures 1-4 depict the trend in IBD prevalence in Israel over the past decade.
Distribution by Age, Gender, and Disease Type: Distribution by age, gender, and disease type is presented in Table 1.
Table 1: Distribution by Age, Gender, and Disease Type:
Figures 1-4: Trend in IBD Prevalence in Israel Over the Last Ten Years.
Figure 5: Socioeconomic Status and IBD Prevalence.
Distribution by Ethnicity and Immigration Status: Among immigrants from the former Soviet Union, there were 3,014 IBD patients, with a relatively equal distribution between Crohn's and ulcerative colitis. The disease rate among Arab Israelis was significantly lower than in the general population (0.22%). Based on a sample of 2,143 Arab patients with IBD, 55% had ulcerative colitis and 45% had Crohn's disease. Ulcerative colitis was more common among this population in all age groups.
Trends Over the Years: Since the computerized calculations began around 2000-2003, we could determine the date of initial diagnosis from 2006 onwards, accounting for the earliest indicative date found in the health fund databases (either diagnosis date or earliest prescription date for IBD medication - the earliest of the two). Additionally, a condition of one year of health fund membership prior to this date was required. Over the past ten years, there has been a trend of increasing Crohn's disease prevalence and a possible decrease in ulcerative colitis (Figure 6). When segmented by age groups, the increase is mainly driven by the 0-14 age group, while the 16-64 age group remains stable and the 65+ age group even sees a decline (Figures 7-9). The increase in Crohn's disease prevalence over ulcerative colitis prevalence over the years (Figure 1), along with the variation in incident rates by age groups, especially in the younger segment, which has both an increasing number of new cases per year and the chronic nature of the disease, can provide insight into the rising and escalating prevalence of IBD in Israel.
Figure 6. IBD occurrences in the population in the last ten years:
Figure 7-9.IBD incidence stratified by age groups:
