Potential missed diagnoses of Crohn's disease in tertiary care: impact on drug utilization and healthcare facilities use

Background: A missed diagnosis of Crohn's disease (CD) can delay treatment initiation with consequences on disease course. Aims: To measure the possible impact of missed diagnoses on drug utilization and access to healthcare facilities in a real-world cohort of CD patients. Methods: This retrospective observational study has been conducted on the regional administrative databases of Tuscany (Italy). We included patients with a first record of CD diagnosis between 06/11/2011 and 06/30/2016. Possible missed diagnosis (exposure) was defined by hospital presentation for gastrointestinal symptoms consistent with CD diagnosis that occurred in the 7-60 months preceding CD diagnosis. We compared exposed and non-exposed patients by assessing time-free from biologic drugs and from Emergency Department (ED) or hospital access. Hazard ratio (HR) was calculated using Cox models. Results: Among 3342 CD patients, 584 (17.5%) had a possible missed diagnosis. A risk of being treated with biologic drugs [adjusted HR (aHR): 2.17, 95% CI: 1.75-2.71] and of access to ED or hospitalization (aHR: 1.59, 95% CI: 1.44-1.75) was observed in patients with a possible missed diagnosis as compared to those without. Conclusion: Tertiary care caregivers should be trained in the identification of early CD symptoms, to timely identify CD diagnosis and optimize pharmacological treatment and disease management.