The Time Course of Diagnostic Delay in Inflammatory Bowel Disease Over the Last Sixty Years: An Italian Multicentre Study

Background and aims: Inflammatory bowel disease [IBD] patients are still under-diagnosed or diagnosed with serious delay. We examined whether diagnostic delay [DD] in IBD has changed over the last 60 years, and explored the risk factors of longer DD.

Methods: In total, 3392 IBD patients recorded in the registry of four IBD Italian centres were divided according to the year of diagnosis into a historical cohort [HC: 1955-84] and modern cohort [MC: 1985-2014]. DD, i.e. time lapse between onset of symptoms indicative of IBD and definitive diagnosis, was divided into four sub-periods [0-6, 7-12, 13-24, >24 months], which were correlated with age and disease location/behaviour at diagnosis.

Results: Median DD in IBD was 3.0 months, it was significantly [P < 0.0001] higher in Crohn's disease [CD] [7.1 months] than in ulcerative colitis [UC] [2.0 months], and did not differ either between the HC and the MC or over the last three decades. However, the proportion of patients with a DD>24 months was significantly [P < 0.0001] higher in the HC [26.0%] than in the MC [18.2%], and the same trend was evident over the last three decades [1985-94: 19.9%; 1995-2004: 16.4%; 2005-14: 13.9%; P = 0.04]. At logistic regression analysis, age at diagnosis >40 years (CD: odds ratio 1.73, 95% confidence interval [CI] 1.31-2.28, P < 0.0001; UC: 1.41, 95% CI 1.02-1.96, P = 0.04) and complicated disease at CD diagnosis [1.39, 95% CI 1.06-1.82, P = 0.02] were independently associated with a DD>24 months.

Conclusions: DD duration has not changed over the last 60 years in Italy, but the number of IBD patients with a longer DD significantly decreased. Older age at diagnosis and a complicated disease at CD diagnosis are risk factors for longer DD.