Diagnostic delay in adult inflammatory bowel disease: A systematic review

BACKGROUND: The extent of diagnostic delay in inflammatory bowel disease (IBD) is incompletely understood. We aimed to understand the extent of diagnostic delay of IBD in adults and identify associations between patient or healthcare characteristics and length of delay. METHODS: Articles were sourced from EMBASE, Medline and CINAHL from inception to April 2021. Inclusion criteria were adult cohorts (18 ≥ years old) reporting median time periods between onset of symptoms for Crohn's disease (CD), ulcerative colitis (UC) or IBD (i.e. CD and UC together) and a final diagnosis (diagnostic delay). Narrative synthesis was used to examine the extent of diagnostic delay and characteristics associated with delay. Sensitivity analysis was applied by the removal of outliers. RESULTS: Thirty-one articles reporting median diagnostic delay for IBD, CD or UC were included. After sensitivity analysis, the majority of IBD studies (7 of 8) reported a median delay of between 2 and 5.3 months. From the studies examining median delay in UC, three-quarters (12 of 16) reported a delay between 2 and 6 months. In contrast, three-quarters of the CD studies (17 of 23) reported a delay of between 2 and 12 months. No characteristic had been examined enough to understand their role in diagnostic delay in these populations. CONCLUSIONS: This systematic review provides robust insight into the extent of diagnostic delay in IBD and suggests further intervention is needed to reduce delay in CD particularly. Furthermore, our findings provide a benchmark value range for diagnostic delay, which such future work can be measured against.