Trends in the prevalence and incidence of Crohn's disease in Japan and the United States.

PURPOSE: This study is to describe patient demographic characteristics and estimate annual prevalence and incidence rates of Crohn's disease (CD) in Japan and the United States (US). METHODS: Two large employment-based healthcare claims databases (Japan Medical Data Center [JMDC] in Japan and Merative MarketScan [Merative] in the US) were used to identify patients with CD from 2010 to 2019. Cases were confirmed using an algorithm based on diagnostic with/without treatment codes. The Merative population was used for sex and age standardization of annual prevalence and incidence rates estimated from the JMDC. RESULTS: Patients with CD were generally younger in Japan than in the US at diagnosis (mean 33.6 vs. 39.4 years) and 71.5% were male versus 45.1% in the US. Annual prevalence per 100,000 population increased substantially in both countries, from 34.2 in 2010 to 54.5 in 2019 in Japan (standardized) and 163.3 to 224.2 in the US. Prevalence rates increased in both males and females in all age groups between 6 and < 65 years. Annual incidence rate per 100,000 person-years was almost fourfold higher in the US than Japan (21.0 vs. 5.5 [standardized] in 2019) but remained stable in both countries over time in both sexes and in all age groups. CONCLUSION: The epidemiology of CD differs between Japan and the US. Research to understand the basis of these differences could help to identify at-risk groups in each country, and guide implementation of preventive measures.

Trends in the prevalence and incidence of ulcerative colitis in Japan and the US.

PURPOSE: To estimate and compare annual prevalence and incidence, and demographic characteristics of patients with ulcerative colitis (UC) in Japan and the United States (US). METHODS: All patients with UC were identified from large employment-based healthcare claims databases (Japan Medical Data Center [JMDC] in Japan and IBM MarketScan Commercial Claims and Encounters database [CCAE] in the US), from 2010 to 2019. Cases were confirmed using International Classification of Disease-9/10 codes with/without Anatomical Therapeutic Chemical codes. Annual age-standardized prevalence and incidence rates were estimated for the JMDC by direct standardization using the CCAE as the standard population. RESULTS: Patients with UC were younger in Japan than in the US and men were affected more than women, whereas the reverse was true in the US. Annual prevalence per 100,000 population increased significantly from 5 in 2010 to 98 in 2019 in Japan and from 158 to 233 in the US. Prevalence increased in men more than in women and in all age groups in Japan, whereas increases were observed similarly in men and women, and in the 6 to < 65-year age groups in the US. Annual incidence per 100,000 person-years increased significantly over time in both sexes and in all age groups in Japan, with higher increases in women and in ≥ 18 year-olds. UC incidence rates did not change over time in the US. CONCLUSION: Ten-year trends in epidemiology of UC differ between Japan and the US. The data point to a growing disease burden in both countries that warrants investigation of measures for prevention and treatment.

Dose titration of osmotic release oral system methylphenidate in children and adolescents with attention-deficit hyperactivity disorder: a retrospective cohort study.

BACKGROUND: Osmotic release oral system methylphenidate (OROS-MPH) is one of the most commonly used medication for attention-deficit hyperactivity disorder (ADHD), however, real-world knowledge on OROS-MPH dose titration has been limited. This study aims to summarize and visualise the OROS-MPH titration patterns in children and adolescents with ADHD in the United States (US) and Japan. METHODS: This retrospective cohort study used the US IBM® MarketScan® Commercial Claims and Encounters database from 2000 to 2019 and the Japan Medical Data Centre database from 2008 to 2019. New OROS-MPH users with ADHD were identified and split into child (6 to < 13 years) and adolescent (13 to < 18 years) groups according to age at OROS-MPH initiation/reinitiation. Patient characteristics and OROS-MPH treatment patterns were described. OROS-MPH dose titration pathways were visualised by Sankey diagrams. RESULTS: We included 98,973 children and 62,002 adolescents in the US cohort, and 4595 children and 1508 adolescents in the Japanese cohort. In Japanese cohort, 91.9% of children and 77.9% of adolescents initiated OROS-MPH at the lowest dose (18 mg/day), whereas US patients had a broader distribution of initial doses (e.g., 18-54 mg/day). The US patients had higher daily dose of OROS-MPH than Japanese patients. Overall, a minority (< 40%) of the OROS-MPH users underwent dose titration, and different titration patterns were observed between the US and Japanese patients. CONCLUSIONS: Different treatment and titration patterns of OROS-MPH were observed in the two countries. Additional real-world studies about clinical reasoning underlying dose selection are needed to support clinical decision-making.