Trends and attributable costs of anorectal involvement in pediatric Crohn's disease

Background: Pediatric Crohn's disease (CD) with anorectal involvement has not been well characterized. We sought to describe trends in the prevalence of pediatric CD with anorectal involvement and its influence on health-care utilization. Materials and methods: Patients (<21 y of age) with an International Classification of Diseases, Ninth Revision diagnosis of CD (555.X) were identified in the Kid's Inpatient Database (2003, 2006, 2009, 2012) and stratified by anorectal involvement based on the International Classification of Diseases, Ninth Revision diagnosis and procedural codes. Patient characteristics and resource utilization (length of stay [LOS] and costs) were compared between CD patients with and without anorectal involvement using univariate and multivariable analyses. Propensity score matching was used to estimate attributable LOS and costs. Results: There were 26,029 patients with CD identified in the study interval. Of these, 1706 (6.6%) had anorectal involvement. Those with anorectal disease were younger (age 16 versus 17 y old), more likely to be male (59.4% versus 49.9%) and black or Hispanic (24.7% versus 18.2%), and were more commonly treated in urban teaching hospitals compared with rural or nonteaching hospitals (83.2% versus 70.9%) (P < 0.001 for all). The proportion of patients with anorectal involvement increased over time (odds ratio 1.03, 95% confidence interval 1.02-1.05). After propensity score matching, attributable LOS and costs were 0.5 d and approximately $1600, respectively. Conclusions: There has been an increase in the proportion of pediatric CD hospitalizations with anorectal manifestations. This pattern of disease is associated with longer hospitalization and higher costs compared with CD alone. Further research is required to understand the underlying etiology of these observed trends.