Background: We have recently shown that the median diagnostic delay
to establish Crohn's disease (CD) diagnosis in the Swiss IBD Cohort
(SIBDC) was 9 months. Seventy five percent of all CD patients were
diagnosed within 24 months. The clinical impact of a long diagnostic
delay on the natural history of CD is unknown.
Aim: To compare the frequency and type of CD-related complications in
the patient groups with long diagnostic delay (>24 months) vs. the ones
diagnosed within 24 months.
Methods: Retrospective analysis of data from the SIBDCS, comprising
a large sample of CD patients followed in hospitals and private
practices across Switzerland.
Results: Two hundred CD patients (121 female, mean age 44.9 ± 15.0
years, 38% smokers, 71% ever treated with immunomodulators and
35% with anti-TNF) with long diagnostic delay were compared to 697
CD patients (358 female, mean age 39.1 ± 14.9 years, 33% smokers,
74% ever treated with immunomodulators and 33% with anti-TNF)
diagnosed within 24 months. No differences in the outcomes were
observed between the two patient groups within year one after CD
diagnosis. Among those diagnosed 2-5 years ago, CD patients with
long diagnostic delay (n = 45) presented more frequently with internal
fistulas (11.1% vs. 3.1%, p = 0.03) and bowel stenoses (28.9% vs.
15.7%, p = 0.05), and they more frequently underwent CD-related
operations (15.6% vs. 5.0%, p = 0.02) compared to the patients
diagnosed within 24 months (n = 159). Among those diagnosed 6-10
years ago, CD patients with long diagnostic delay (n = 48) presented
more frequently with extraintestinal manifestations (60.4% vs. 34.6%,
p = 0.001) than those diagnosed within 24 months (n = 182). For the
patients diagnosed 11-15 years ago, no differences in outcomes were
found between the long diagnostic delay group (n = 106) and the one
diagnosed within 24 months (n = 32). Among those diagnosed >= 16
years ago, the group with long diagnostic delay (n = 71) more frequently
underwent CD-related operations (63.4% vs. 46.5%, p = 0.01)
compared to the group diagnosed with CD within 24 months (n = 241).
Conclusions: A long diagnostic delay in CD patients is associated with
a more complicated disease course and higher number of CD-related
operations in the years following the diagnosis. Our results indicate that
efforts should be undertaken to shorten the diagnostic delay in CD
patients in order to reduce the risk for progression towards a
complicated disease phenotype.