Background We aimed to explore the epidemiology of inflammatory bowel diseases (IBD) in association with 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 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 annual incidence of IBD was stable until 2019 in both countries and since, it decreased in Israel (AAPC of -16.6% [95%CI -19.9% to -10.0%]) and remained stable in Sweden (AAPC of -3.5% [95%CI -11.6% to 3.7%]). When exploring the monthly incidence during the pandemic, in Israel the rate 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, it 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%]). The change of incidence rate in Sweden occurred mainly in elderly-onset patients, the only population with significant restrictions during the pandemic. Conclusion The incidence of IBD decreased during the pandemic in association with lockdowns, more so in Israel, which had more stringent policies. Future studies are needed to determine the long-term effect of the pandemic on IBD.

中文翻译：

---

COVID-19 大流行期间炎症性肠病的流行病学：两个全国队列的比较

背景我们的目的是探讨两个实行不同封锁政策的国家中与 COVID-19 大流行相关的炎症性肠病 (IBD) 的流行病学。方法 我们利用以色列和瑞典的全国 IBD 队列来探讨大流行期间与三年前（2017-2019 年）相比的 IBD 发病率。我们通过 Joinpoint 回归分析通过拐点的存在检查了时间趋势，并报告了平均每月百分比变化 (AMPC)。结果 总共纳入了 155,837 名 IBD 患者（以色列，58,640 名；瑞典，97,197 名）。两国 IBD 的年发病率在 2019 年之前保持稳定，此后以色列的发病率有所下降（AAPC 为 -16.6% [95%CI -19.9% 至 -10.0%]），瑞典则保持稳定（AAPC 为 -3.5% [ 95% CI -11.6% 至 3.7%]）。在探讨大流行期间的每月发病率时，以色列的发病率直到 2020 年 11 月才保持稳定（AMPC 2.3% [95%CI -13.4% 至 29.9%]），然后急剧下降（AMPC -6.4% [95%CI-20.8%]）到 17.0%]），直到 2021 年 2 月，为 -20.1% [95%CI -38.9% 到 -4.7%]），从 2021 年 2 月开始），而在封锁政策不太严格的瑞典，到 2020 年 7 月，这一数字略有下降（AMPC -3.3% [95%CI -21.6% 至 20.3%]），但此后有所增加（AMPC 13.6% [95%CI -12.6% 至 27.0%]）。瑞典发病率的变化主要发生在老年发病患者中，这是大流行期间唯一受到严格限制的人群。结论 在大流行期间，IBD 发病率下降与封锁有关，在政策更为严格的以色列尤其如此。未来的研究需要确定大流行对 IBD 的长期影响。