P1097 The effect of lockdowns during the COVID-19 pandemic on the epidemiology of inflammatory bowel diseases: a comparison of two nationwide cohorts

Abstract

Abstract Background Mechanistic evidence suggest a link between COVID-19 infections and the development of immune mediated diseases. Additionally, the lockdowns during the pandemic limited the accessibility to medical care, possibly leading to reduced number of diagnosed patients with inflammatory bowel disease (IBD). We aimed to explore these contending trends on the epidemiology of IBD during the COVID-19 pandemic in two countries with different lockdown policies. Methods We utilized nationwide IBD cohorts in Israel and Sweden to explore the incidence of IBD during the pandemic (2020-2021) compared to three years prior (2017- 2019). We examined temporal trends through the presence of inflection points by Joinpoint regression analysis and reported average monthly percentage changes (AMPC). Results A total of 155,837 patients with IBD were included (Israel, 58,640; Sweden, 97,197). The incidence of IBD was stable during the three years prior to the beginning of the COVID-19 pandemic in February 2020 (AMPC: Israel 0.0% [95%CI -0.5% to 0.4%]; Sweden 0.2% [95%CI -0.3% to 0.7]). Thereafter, the incidence rate in Israel remained stable until November 2020 (AMPC 2.3% [95% CI -13.4% to 29.9%]) and then decreased sharply (AMPC -6.4% [95%CI-20.8% to 17.0%]) until February 2021 and -20.1% [95%CI -38.9% to -4.7%]) from February 2021), while in Sweden, which had a less stringent lockdown policy, the incidence rate decreased slightly until July 2020 (AMPC -3.3% [95%CI -21.6% to 20.3%]), but increased thereafter (AMPC 13.6% [95%CI -12.6% to 27.0%]; Figure). In Israel, the reduced incidence rate during the pandemic (February 2020 to July 2021) was notable mainly in the adult-onset disease, while in Sweden, although the overall incidence rate increased steadily across all age groups, the largest change was apparent among the elderly. Conclusion In this study of two nationwide cohorts we found that the initial decrease in incidence of IBD was most apparent in Israel with a more stringent lookdown policy and among elderly in Sweden, the only population there with significant social restrictions during the pandemic. Taken together, it is likely that the reduced incidence stemmed from the limited access to the healthcare system. Future studies are needed to determine the long-term effect of the pandemic on IBD incidence.