Objective: Medical information databases provide useful Real World Evidence (RWE) and a comprehensive view of medical activities. However, since each database has limited coverage and cannot be self-sufficient, combining information from multiple databases is a useful research technique. In this study, we examined methods of estimating patient numbers by combining information from multiple databases in order to assess the respective databases and identify the respective characteristics, biases and idiosyncrasies. This process also allowed us to propose improvements in the grand design of medical information databases in Japan.
Design: Retrospective observational cohort study
Methods: We attempted to estimate the numbers of patients treated for certain diseases and the numbers prescribed a drug by three methods: i) We estimated patient numbers for seven diseases using an insurance claims database, adjusting the proportion of elderly patients according to a hospital medical records database; ii) Sales information for drug X was combined with the prescribed volume per person estimated from pharmacy claims databases to estimate the number of patients administered X; this number was divided by the prescription rate obtained from a medical claims database to calculate patient numbers for the associated disease; and iii) We examined two surveys of the National Institute of Infectious Diseases (NIID) for timely estimation of patient numbers for influenza, referring to estimates from an insurance claims database.
Results: In Method i)-iii), we proved that it is possible to estimate patient numbers for many diseases and administered drugs by effectively combining multiple medical information databases. Validation could be claimed when multiple methods lead to similar results.
Conclusion: These databases provided by government agencies and private corporations are separately managed, and there is no grand plan to integrate them into one platform. It is crucial that databases, rather than being designed to stand alone, are standardized according to widely used systems under a solid master data management strategy. This will make it easier to combine information from multiple databases and to maximize their values. Mutual use of these databases by academic researchers for epidemiological and clinical studies and by government policy makers and data scientists of pharmaceutical companies may improve the usefulness of these databases and expand their application in research.

Background/Aims: Endoscopic activity confirmed by enteroscopy is associated with poor clinical outcome in Crohn’s disease (CD). We investigated which of the existing biomarkers best reflects endoscopic activity in CD patients including the small bowel, and whether their combined use can improve accuracy. Methods: One hundred and four consecutive patients with ileal and ileocolonic type CD who underwent balloon-assisted enteroscopy (BAE) from October 2021 to August 2022 were enrolled, with clinical and laboratory data prospectively collected and analyzed. Results: Hemoglobin, platelet count, C-reactive protein, leucine-rich alpha-2 glycoprotein (LRG), fecal calprotectin, and fecal hemoglobin all showed significant difference in those with ulcers found on BAE. LRG and fecal calprotectin showed the highest areas under the curve (0.841 and 0.853) for detecting ulcers. LRG showed a sensitivity of 78% and specificity of 80% at a cutoff value of 13 μg/mL, whereas fecal calprotectin showed a sensitivity of 91% and specificity of 67% at a cutoff value of 151 μg/g. Dual positivity for LRG and fecal calprotectin, as well as LRG and fecal hemoglobin, both predicted ulcers with an improved specificity of 92% and 100%. A positive LRG or fecal calprotectin/hemoglobin showed an improved sensitivity of 96% and 91%. Positivity for LRG and either of the fecal biomarkers was associated with increased risk of hospitalization, surgery, and relapse. Conclusions The biomarkers LRG, fecal calprotectin, and fecal hemoglobin can serve as noninvasive and accurate tools for assessing activity in CD patients confirmed by BAE, especially when used in combination.

Background/Aims: The efficacy and safety of tofacitinib for the treatment of refractory ulcerative colitis (UC) has been demonstrated in clinical trials. Although, a series of reports with real-world evidence of its short-term efficacy and safety profiles have already been published, reports of long-term real-world data have been limited. We aimed to show our 3-year evidence on the clinical use of tofacitinib for the treatment of UC, focusing on its efficacy and safety profiles. Methods: A retrospective observational study was conducted on patients who started tofacitinib for active refractory UC at our hospital. The primary outcome was the retention rate until 156 weeks after initiating tofacitinib. The secondary outcomes were short-term efficacy at 4, 8, and 12 weeks; long-term efficacy at 52, 104, and 156 weeks; prognostic factors related to the cumulative retention rate; loss of response; and safety profile, including adverse events. Results: Forty-six patients who were able to be monitored for up to 156 weeks after tofacitinib initiation, were enrolled in this study. Continuation of tofacitinib was possible until 156 weeks in 54.3%, with > 50% response rates and > 40% remission rates. Among patients in whom response or remission was achieved and tofacitinib was deescalated after 8 weeks of induction treatment, 54.3% experienced relapse but were successfully rescued by and retained on reinduction treatment, except for 1 patient. No serious AEs were observed in the study. Conclusions Tofacitinib is effective and safe as long-term treatment in a refractory cohort of UC patients in real-world clinical practice.