NDBを用いた新たな患者追跡手法の開発

The National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) is a comprehensive database containing health insurance claim information. The structure of the NDB complicates long-term cohorts for two main reasons. First, the NDB data are stored on a per-claim basis. Second, the NDB is a billing-focused record structure. Therefore, the objective of this study was to use ID0 to modify the data structure to allow for long-term cohorts, provided that the data volume is not increased and the runtime per data year is maintained within one month. The NDB uses two primary keys (ID1 and ID2) made from hash values that mask personally identifiable information. ID0 is our recently developed key from ID1 and ID2, which improves patient-matching efficiency with excellent long-term tracing performance. Our study used claim data with filing dates between April 2013 and March 2016 to trace hospitalizations of one month or longer, including outpatient care, in three steps. In Step 1, claims were transferred to a CD-record format. As some diagnosis procedure combination (DPC) claim records contain a mixture of overlapping comprehensive and piece-rate data, we sorted and reorganized them. In Step 2, pharmacy and medical outpatient claims were integrated using the ID0 key, the medical institution code for issuing a prescription, and the prescription issue date. In Step 3, the transferred data were combined and converted from consecutive hospitalization days into sequences based on ID0, the medical institution code, and hospital ward classification. Consequently, the size of the originally extracted comma-separated variable dataset for three years (approximately 10.5 TB) was reduced to an approximately 6 TB main database file that was usable for processing. The process took approximately three months. With similar conventional methods, the data size was 30 times larger, and it took more than seven months to process a year's worth of data. In addition, to demonstrate the application of this method, we conducted a six-year mortality cohort for all Japanese citizens. Our technique makes it easy to perform follow-up and longitudinal cohort surveys while accurately tracing patient data in large-scale medical claims databases.博士（医学）・甲第854号・令和4年12月22日Copyright: ©2022 The Author(s). This is an open access article distributed under the terms of the Creative Commons BY 4.0 International (Attribution) License (https:// creativecommons.org/licenses/by/4.0/legalcode), which permits the unrestricted distribution, reproduction and use of the article provided the original source and authors are credited

季節と天候による骨折リスクの差 : 日本のレセプト情報データベースを用いた、全ての年齢・部位に関する包括的な分析

Although age- and season-specific effects on fracture risk have been reported, the effects of seasonality across different age groups and for different fracture sites have not yet been clarified. Therefore, our study aimed to comprehensively investigate the effects of seasonality on fracture risk across age and fracture sites using a large-scale population database of fracture incidence. Fracture data were accumulated over a 3-year period in the region of Tokyo and in surrounding areas, which accounts for a total population of 42 million. Information on fracture occurrence, fracture site, and patient demographics were obtained from the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB). Over the study period, 508,051 fractures were identified across the following five age groups: 0-19, 20-39, 40-64, 65-79, and 80+ years. The incidence rate for fractures in 10 site groups was calculated. Fracture risk was the highest in the spring and autumn for children aged 0-19 years and was the highest in the winter for elderly individuals (65-79 and 80+ years). Toe fractures, which occurred more frequently in the summer, were the most notable exception. The risk of fracture of the distal radius and hip was associated with daily temperature and rainfall and was elevated on days with a mean temperature higher than that of the previous day. Fracture risk exhibited seasonal variations that differed between children and elderly individuals and between toe fractures and fractures at other sites. These findings can help us understand the epidemiology of fractures and develop preventive strategies, as well as aid in the allocation of healthcare resources.博士（医学）・甲第718号・令和元年9月27

日本における保険診療全透析患者追跡と死亡数の現状

Background: The survival rate of chronic dialysis patients in Japan remains the highest worldwide, so there is value in presenting Japan's situation internationally. We examined whether aggregate figures on dialysis patients in the National Database of Health Insurance Claims and Special Health Checkups of Japan (NDB), which contains data on insured procedures of approximately 100 million Japanese residents, complement corresponding figures in the Japanese Society for Dialysis Therapy Renal Data Registry (JRDR). Methods: Subjects were patients with medical fee points for dialysis recorded in the NDB during 2014-2018. We analyzed annual numbers of dialysis cases, newly initiated dialysis cases- and deaths. Results: Compared with the JRDR, the NDB had about 6-7% fewer dialysis cases but a similar number of newly initiated dialysis cases. In the NDB, the number of deaths was about 6-10% lower, and the number of hemodialysis cases was lower, while that of peritoneal dialysis cases was higher. The cumulative survival rate at dialysis initiation was approximately 6 percentage points lower in the NDB than in the JRDR, indicating that some patients die at dialysis initiation. Cumulative survival rate by age group was roughly the same between the NDB and JRDR in both sexes. Conclusion: The use of the NDB enabled us to aggregate data of dialysis patients. With the definition of dialysis patients used in this study, analyses of concomitant medications, comorbidities, surgeries, and therapies will become possible, which will be useful in many future studies.博士（医学）・甲第818号・令和4年3月15日© 2021. The Author(s).　Open Access This article is licensed under a Creative Commons Attri bution 4.0 International License, which permits use, sharing, adapta tion, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/

後期高齢者における人工栄養開始後の生命予後 : 医科レセプトデータを用いたコホート研究

Background: Enteral feeding and parenteral nutrition (PN) using gastrostomy (GS) and a nasogastric tube feeding (NGT) and PN should be initiated for older patients based on their prognoses. This study aimed to investigate the long-term prognosis of patients aged ≥75 years who underwent enteral feeding via GS and NGT as well as PN. Methods: A population-based cohort study was conducted using Japan's universal health insurance claims in the Nara Prefecture. This study enrolled 3,548 patients aged ≥75 years who received GS (N=770), NGT (N=2,370), and PN (N=408) during hospital admissions between April 2014 and March 2016. The GS group was further categorized into secondary GS (N=400) with preceding NGT or PN within 365 days and primary GS (N=370) without preceding NGT or PN groups. In the secondary GS group, 356 (96%) patients received NGT (versus PN). The outcome was mortality within 730 days after receiving GS, NGT, and PN. Cox regression analyses in cases with or without malignant diseases, adjusted for sex, age, comorbidity, and hospital type, were performed to compare mortality in the groups. Results: Of the 3,548 participants, 2,384 (67%) died within 730 days after the initiation of GS and NGT and PN. The 2-year mortality rates in the secondary GS, primary GS, NGT, and PN groups were 58%, 66%, 68%, and 83% in patients without malignancies and 67%, 71%, 74%, and 87% in those with malignancies, respectively. In the non-malignant group, Cox regression analysis revealed that secondary GS (hazard ratio (HR) = 0.43, 95% CI: 0.34-0.54), primary GS (HR = 0.51, 95% CI: 0.40-0.64), and NGT (HR = 0.71, 95% CI: 0.58-0.87) were statistically significantly associated with lower mortality compared with PN. Conclusions: Approximately 58% to 87% patients aged ≥75 years died within 730 days after initiation of nutrition through GS, NGT, or PN. Patients with non-malignant diseases who received secondary GS exhibited better 2-year prognosis than those who received NGT or PN. Healthcare professionals should be aware of the effectiveness and limitations of enteral feeding and PN when considering their initiation.博士（医学）・甲第793号・令和3年6月25日Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data

日本の百寿者及び非百寿者における死亡前1年間に発生する医療費の比較

Importance: Although research has shown that centenarians tend to experience shorter periods of serious illness compared with other age groups, few studies have focused on the medical expenditures of centenarians as a potential indicator of the scale of medical resources used in their last year of life. Objective: To compare Japanese centenarians' and noncentenarians' monthly medical expenditures during the year before death according to age and sex. Design, setting, and participants: This retrospective cohort study used linked national health and long-term care insurance data collected from April 2013 to March 2018 in Nara Prefecture, Japan, for residents aged 75 years or older who were insured under the Medical Care System for older adults and died between April 2014 and March 2018. Data were analyzed from April 2013 to March 2018. Exposures: Age of 100 years or older (centenarians) vs 75 to 99 years (noncentenarians). Main outcomes and measures: The numbers of unique inpatients and outpatients and medical expenditures related to decedents' hospitalization and outpatient care were extracted and analyzed based on sex and age group. The Jonckheere-Terpstra test was used to identify trends in unadjusted medical expenditures by age group, and generalized estimating equations were used to estimate monthly median expenditures by age group with adjustment for comorbidity burden and functional status. Results: Of 34 317 patients aged 75 to 109 years (16 202 men [47.2%] and 18 115 women [52.8%]) who died between April 2014 and March 2018, 872 (2.5%) were aged 100 to 104 years (131 men [15.0%] and 741 women [85.0%]) and 78 (0.2%) were aged 105 to 109 years (fewer than 10 were men). The analysis of unadjusted medical expenditures in the last year of life showed a significant trend of lower expenditures for the older age groups; the median adjusted total expenditures during the 30 days before death by age group were $6784 (IQR,$4884-$9703) for ages 75 to 79 years,$5894 (IQR, $4292-$8536) for 80 to 84 years, $5069 (IQR,$3676-$7150) for 85 to 89 years,$4205 (IQR, $3085-$5914) for 90 to 94 years, $3522 (IQR,$2626-$4861) for 95 to 99 years,$2898 (IQR, $2241-$3835) for 100 to 104 years, and $2626 (IQR,$1938-$3527) for 105 to 109 years. The proportion of inpatients among all patients in the year before death also decreased with increasing age: 4311 of all 4551 patients aged 75 to 79 years (94.7%); 43 of all 78 patients aged 105 to 109 years (55.1%); 2831 of 2956 men aged 75 to 79 years (95.8%); 50.0% of men aged 105 to 109 years (the number is not reported owing to the small sample size); 1480 of 1595 women aged 75 to 79 years (92.8%); and 55.7% of women aged 105 to 109 years (the number of women is not reported to prevent back-calculation of the number of men). Specifically, 274 of 872 patients aged 100 to 104 years (31.4%) and 35 of 78 patients aged 105 to 109 years (44.9%) had not been admitted to a hospital in the year before death. Conclusions and relevance: This cohort study found that medical expenditures in the last year of life tended to be lower for centenarians than for noncentenarians aged 75 years or older in Japan. The proportion of inpatients also decreased with increasing age. These findings may inform future health care services coverage and policies for centenarians.博士（医学）・甲第801号・令和3年12月21日© 2021 Nakanishi Y. et al.JAMA Network Open. Open Access: This is an open access article distributed under the terms of the CC-BY License(https://creativecommons.org/licenses/by/4.0/)

Data regarding fracture incidence according to fracture site, month, and age group obtained from the large public health insurance claim database in Japan

The National Database of Health Insurance Claims and Specific Health Checkups of Japan includes all health insurance claims submitted in Japan and is considered representative of almost all health claims in Japan. Data regarding fracture incidence, based on the documented diagnoses in the claims and relevant procedure codes, were extracted from the National Database of Health Insurance Claims and Specific Health Checkups of Japan. This data paper includes fracture incidence according to fracture site, month, and age group for the population in Kanto area (Tokyo and surrounding areas), which consists of approximately 42 million people. These data provide supplementary material to be interpreted for the article “Variation in Fracture Risk by Season and Weather: A Comprehensive Analysis across Age and Fracture Site Using a National Database of Health Insurance Claims in Japan” Hayashi et al., and serve as one of the largest epidemiological datasets regarding seasonal differences in fracture incidence according to fracture site and age group. Keywords: Epidemiology, Fracture, Season, National database, Health insurance claims, Japa