Association of diagnostic delay with medical cost for patients with Crohn's disease: A Japanese claims‐based cohort study

Background and Aim: Longer diagnostic delay (DD) in Crohn's disease (CD) is associated with complications and related surgeries. However, the impact of DD on medical cost after CD diagnosis remains uncertain.Methods: This was a claims-based cohort study. Our analysis used data from 2005 to 2018 from the Japanese Claims Database. We enrolled a total of 528 newly diagnosed CD patients (76.9% male) aged 31.5 +/- 13.6 years. High medical cost was defined as the highest quartile of the average monthly medical cost. DD was defined as the interval between the first visit to a gastroenterologist and diagnosis with CD. In the multivariable logistic regression analysis, patients were stratified by the use of anti-tumor necrosis factor alpha (anti-TNF alpha) agents to exclude their influence on the observed effects. This study was approved by the ethics review board of the Juntendo University Faculty of Medicine (No. 2019178).Results: The multivariable-adjusted odds ratios and 95% confidence intervals of high medical cost were 1.41 (0.81-2.43) and 0.91 (0.57-1.46), respectively, for a DD of >12 months and 1 to <= 12 months compared to <1 month. In patients receiving anti-TNF alpha agents, the multivariable-adjusted odds ratios for high medical cost were 2.63 (1.34-5.16) and 1.35 (0.79-2.28) for a DD of >12 months and 1 to <= 12 months, respectively, compared to <1 month. In patients without anti-TNF alpha, multivariable logistic regression analyses were not presented because of a small number of patients categorized into the high medical cost group.Conclusion: A delayed diagnosis of CD may incur high medical cost in patients who develop aggressive disease that requires treatment with anti-TNF alpha agents.