Background:The impact of diagnostic delay on the clinical course of inflammatory bowel disease (IBD) remains uncertain.Aim: To perform a systematic review of time to diagnosis and the impact of delayed diagnosis on clinical outcomes in Crohn's disease (CD) and ulcerative colitis (UC). Methods:We searched EMBASE and Medline from inception to 30th November 2022 for studies reporting diagnostic interval, from symptom onset to IBD diagnosis.We calculated the median, interquartile range (IQR) and pooled weighted median, of median diagnostic intervals of eligible studies. We defined delayed diagnosis as individuals above the 75th centile of longest time to diagnosis in each study. Using random effects meta-analysis, we pooled odds ratios (ORs) with 95% confidence intervals (CI) for studies reporting clinical outcomes, according to delayed diagnosis.Results: One hunderd and one studies representing 112,194 patients with IBD (CD = 59,359; UC = 52,835) met inclusion criteria. The median of median times to diagnosis was 8.0 (IQR: 5.0-15.2) and 3.7 months (IQR: 2.0-6.7) in CD and UC, respectively. In high-income countries, this was 6.2 (IQR: 5.0-12.3) and 3.2 months (IQR: 2.2-5.3), compared with 11.7 (IQR: 8.3-18.0) and 7.8 months (IQR: 5.2-21.8) in low-middle-income, countries, for CD and UC respectively. The pooled weighted median was 7.0 (95% CI: 3.0-26.4) and 4.6 (95% CI: 1.0-96.0) months, for CD and UC respectively. Eleven studies, representing 6164 patients (CD = 4858; UC = 1306), were included in the meta-analysis that examined the impact of diagnostic delay on clinical outcomes. In CD, delayed diagnosis was associated with higher odds of stric-

ObjectiveUstekinumab is an interleukin-12/interleukin-23 receptor antagonist licensed for the treatment of ulcerative colitis (UC). Clinical trial data were promising; however, real-world data are limited. We assessed the safety and effectiveness of ustekinumab in UC in a real-world setting.Design/methodThis was a multicentre, retrospective, observational cohort study between February 2020 and January 2022. Disease activity was assessed using the Simple Clinical Colitis Activity Index (SCCAI). Clinical remission was defined as a SCCAI≤2. The primary endpoints were rates of corticosteroid-free remission (CSFR) at week 16 and at week 26. Objective outcomes, including faecal calprotectin (FCAL), were also collected.Results110 patients with UC (65% male; median age 40 (IQR range 29–59); 96% with prior biologic and/or tofacitinib exposure) had a median follow-up of 28 weeks (IQR 17–47). CSFR was 36% (18/50) at week 16% and 33% (13/39) at week 26, corresponding with a significant fall in SCCAI from 6 (IQR 4–8) at baseline to 3 (IQR 0–5) at week 26, p<0.001. By week 16, there was improvement of median FCAL measurements, which fell from a baseline of 610 µg/g (IQR 333–1100) to 102 µg/g (IQR 54–674) at week 16. At the end of follow-up, 15% (17/110) had discontinued treatment; 13 patients due to primary non-response or loss of response, and 1 patient for family planning. Treatment was discontinued in three patients due to adverse events.ConclusionIn the largest real-world study to date, ustekinumab was effective with a reassuring safety profile in a refractory cohort of patients.

LINKED CONTENTThis article is linked to Jayasooriya et al papers. To view these articles, visit https://doi.org/10.1111/apt.17370 and https://doi.org/10.1111/apt.17483.