DIAGNOSIS CHANGES IN PEDIATRIC IBD: DATA FROM THE IMPROVECARENOW REGISTRY

Background The change in subclassification of inflammatory bowel diseases (IBD) among patients with Crohn’s (CD), ulcerative colitis (UC), and IBD-unclassified (IBD-u) has previously been described in subpopulations of adult and pediatric patients. To date, no large, multinational registries have described characteristics of pediatric patients who change diagnosis. Methods We used the largest (27,628 individual patients for this study) prospective registry in the world for pediatric patients with IBD, ImproveCareNowR (ICN) to characterize those who change diagnosis. Diagnosis in the ICN registry is based on the Paris classification. Results 7.52% of pediatric patients had any change in diagnosis; 5.19% of patients experienced a change in diagnosis after the initial 3 visits (Table 1). Those who start with a diagnosis of Crohn’s are more likely to change, as compared with starting diagnoses of ulcerative colitis or IBD-u (p < 0.05). A majority of changes involve a diagnosis of IBD-u (75.8%, Figure 1). Among those who change diagnoses, those with initial diagnoses of Crohn’s or IBD-u are more likely to have a BMI Z-score of less than -2, as compared to those with initial diagnosis of UC (p < 0.05). Patients with initial diagnosis of Crohn’s who changed after 3 visits were less likely to have ileocolonic extent, penetrating or stricturing phenotype, or perianal disease documented (p < 0.05). Signs of initial miscoding occurred in less than 0.3% of patients. Discussion This is the first reported use of a large prospective pediatric registry to investigate diagnosis changes within IBD. Registration diagnosis of Crohn’s appears to have more clinically impactful findings than those with UC or IBD-u. A majority of all changes involved a diagnosis of IBD-unclassified. Further investigation of diagnosis changes across time and modeling will supplement our understanding of clinical factors predictive of change.