Incidence and seasonality of type 1 diabetes: a population-based 3-year cohort study using the National Database in Japan

Literature Review of Studies Using the National Database of the Health Insurance Claims of Japan (NDB): Limitations and Strategies in Using the NDB for Research

The use of the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) for research has increased over time. Researchers need to understand the characteristics of the data to generate quality-assured evidence from the NDB. In this review, we mapped and characterized the limitations and related strategies using the NDB for research based on the descriptions of published NDB studies. To find studies that used Japanese healthcare claims data, we searched MEDLINE, EMBASE, and Ichushi-Web up to June 2023. Additionally, we hand-searched the NDB data publication list from the Ministry of Health, Labour and Welfare (2017-2023). We abstracted data based on the NDB data type, research themes, age of the study sample or population, targeted disease, and the limitations and strategies in the NDB studies. Ultimately, 267 studies were included. Overall, the most common research theme was describing and estimating the prescriptions and treatment patterns (125 studies, 46.8%). There was a variation in the frequency of themes according to the type of NDB data. We identified the following categories of limitations: (1) lack of information on confounders/covariates, outcomes, and other clinical content, (2) limitations regarding patients not included in the NDB, (3) misclassification of data, (4) lack of unique identifiers and register of beneficiaries, and (5) others. Although the included studies noted several limitations of using the NDB for research, they also provided some strategies to address them. Organizing the limitations of NDB in research and the related strategies across research fields can help support high-quality NDB studies.

An age-stratified cross-sectional study of antidiabetic and non-antidiabetic drugs prescribed to Japanese outpatients with diabetes

Polypharmacy, common in patients with diabetes, may cause adverse drug reactions. The number of antidiabetic and non-antidiabetic drugs prescribed to patients in different age groups remains unclear. The aim of this study was to examine the number and class of antidiabetics and non-antidiabetics prescribed to Japanese patients with diabetes, stratified by age for reducing polypharmacy. This cross-sectional study examined all prescriptions of patients prescribed antidiabetics at 257 pharmacies of Matsumotokiyoshi Holdings in Japan from May 2018 to March 2019. Total prescription numbers including antidiabetic drugs were 263,915 in this study. Mean numbers of antidiabetic drugs per prescription were 1.71, 2.17, and 1.52 in the patient age groups of 10-19, 50-59, and 90-99 years, respectively. Count of antidiabetics was not related to age. However, the mean total number of drugs prescribed increased with age, which was 2.22 and 7.99 in the age groups of 10-19 and 90-99 years, respectively. The linear regression coefficient (b) according to age was 0.07 (p < 0.001) for 10-99 years. The mean non-antidiabetic number of agents prescribed increased with age among 10-99 years (b = 0.07, p < 0.001). Among outpatients treated for diabetes, dipeptidyl peptidase-4 inhibitors (29%) and antihypertensive, β-blocking and renin-angiotensin system blocking drugs (32%) were the most prescribed antidiabetics and non-antidiabetics in all ages, respectively. The number of prescribed antidiabetic agents did not increase with age, whereas the total and non-antidiabetic numbers of medications prescribed increased linearly. For reduction of polypharmacy in older people with diabetes, we need to focus on non-antidiabetics.

Virtual patient identifier (vPID): Improving patient traceability using anonymized identifiers in Japanese healthcare insurance claims database

Objective

Japan's national-level healthcare insurance claims database (NDB) is a collective database that contains the entire information on healthcare services being provided to all citizens. However, existing anonymized identifiers (ID1 and ID2) have a poor capability of tracing patients' claims in the database, hindering longitudinal analyses. This study presents a virtual patient identifier (vPID), which we have developed on top of these existing identifiers, to improve the patient traceability.

Methods

vPID is a new composite identifier that intensively consolidates ID1 and ID2 co-occurring in an identical claim to allow to collect claims of each patient even though its ID1 or ID2 may change due to life events or clerical errors. We conducted a verification test with prefecture-level datasets of healthcare insurance claims and enrollee history records, which allowed us to compare vPID with the ground truth, in terms of an identifiability score (indicating a capability of distinguishing a patient's claims from another patient's claims) and a traceability score (indicating a capability of collecting claims of an identical patient).

Results

The verification test has clarified that vPID offers significantly higher traceability scores (0.994, Mie; 0.997, Gifu) than ID1 (0.863, Mie; 0.884, Gifu) and ID2 (0.602, Mie; 0.839, Gifu), and comparable (0.996, Mie) and lower (0.979, Gifu) identifiability scores.

Discussion

vPID is seemingly useful for a wide spectrum of analytic studies unless they focus on sensitive cases to the design limitation of vPID, such as patients experiencing marriage and job change, simultaneously, and same-sex twin children.

Conclusion

vPID successfully improves patient traceability, providing an opportunity for longitudinal analyses that used to be practically impossible for NDB. Further exploration is also necessary, in particular, for mitigating identification errors.

Dose Rationale of Nasal Glucagon in Japanese Pediatric Patients with Diabetes Using Pharmacokinetic/Pharmacodynamic Modeling and Simulation

BACKGROUND

Nasal glucagon (NG) 3 mg is approved in Japan to treat hypoglycemia in pediatric patients with diabetes, but an NG clinical study has not been performed in Japanese children because of practical and ethical concerns.

OBJECTIVE

The aim of this study is to support the dose rationale for NG 3 mg in Japanese pediatric patients with diabetes using modeling and simulation.

METHODS

We used a pharmacokinetic/pharmacodynamic bridging approach to extrapolate the available clinical data to Japanese pediatric patients. Population pharmacokinetic/pharmacodynamic modeling was performed using data from seven clinical studies, including five studies in non-Japanese adults, one study in Japanese adults, and one study in non-Japanese pediatric patients. Simulation was then used to estimate glucagon exposure and glucose response after NG 3-mg administration for three age categories of Japanese pediatric patients: 4 to < 8, 8 to < 12, and 12 to < 18 years. Treatment success was defined as an increase in blood glucose to ≥ 70 or ≥ 20 mg/dL from nadir within 30 min after administration of NG 3 mg. Safety was assessed in relation to the predicted maximum glucagon concentration of NG 3 mg using NG clinical trial data and published data on intravenous and intramuscular glucagon.

RESULTS

The data showed a rapid and robust glucose response following NG 3 mg in Japanese and non-Japanese adults and non-Japanese pediatric patients, with some differences in glucagon exposure observed across studies. The pharmacokinetic/pharmacodynamic model described the observed clinical data well, and simulations indicated that > 99% of hypoglycemic Japanese pediatric patients in all three age groups would achieve treatment success. Predicted glucose responses to NG 3 mg in Japanese pediatric patients were comparable to those of intramuscular glucagon. Maximum concentration was not associated with the occurrence and severity of common adverse events (nausea, vomiting, and headache) in NG clinical studies. Furthermore, the predicted maximum concentration in Japanese pediatric patients, despite being higher than the observed maximum concentration in NG clinical studies, was substantially lower than the observed maximum concentration of 1 mg of intravenous glucagon, without serious safety issues.

CONCLUSIONS

This analysis suggests NG 3 mg has robust efficacy without serious safety concerns in Japanese pediatric patients with diabetes.

Incidence of Childhood Type 1 Diabetes in Beijing During 2011-2020 and Predicted Incidence for 2025-2035: A Multicenter, Hospitalization-Based Study

INTRODUCTION

China has a low incidence of type 1 diabetes mellitus (T1DM); however, based on the large population, the absolute numbers are high. Our aim was to assess the incidence of childhood T1DM in Beijing during 2011-2020, predicted incidence for 2025-2035, and to determine the incidence of diabetic ketosis or diabetic ketoacidosis (DK/DKA) in this population.

METHODS

Data on patients aged less than 15 years of age with newly diagnosed T1DM between January 1, 2011 and December 31, 2020 was obtained from five tertiary hospitals in Beijing and retrospectively analyzed.

RESULTS

In all, 636 children aged less than 15 years were diagnosed with T1DM during 2011-2020. The incidence of T1DM was 3.11-5.46 per 100,000 per year, with an average increase of 5.10% per year. The age-specific incidence for ages 0-4 years, 5-9 years, and 10-14 years was 2.97, 4.69, and 4.68 per 100,000 per year, respectively. The highest average annual increase (7.07%) in incidence was for the youngest age group. DK or DKA was present at the time of diagnosis of T1DM in 84.6% of patients. The age-specific incidence of T1DM among children aged less than 15 years was predicted to be 7.32, 11.4, and 11.52 per 100,000 in 2035 for ages 0-4 years, 5-9 years, and 10-14 years, respectively.

CONCLUSIONS

The was a gentle increase in the incidence of childhood T1DM during 2011-2020 in Beijing. This increase is expected to continue for the next 15 years.

Seasonal exacerbation of rheumatoid arthritis detected by big claims data analysis: A retrospective population study

OBJECTIVES

The objective of the study was to determine the seasonal changes in the initiation of biological disease-modifying antirheumatic drugs (bDMARDs) and methotrexate (MTX) using big claims data.

METHODS

We counted the monthly number of initial administrations of each bDMARD and MTX in patients with rheumatoid arthritis (RA) between April 2010 and March 2017. Data were collected from the National Database of Health Insurance Claims and Specific Health Checkups of Japan. This database covers more than 95% of Japanese citizens. Seasonal changes in the number of initiations were determined. Patient claims were also classified according to drugs, districts, gender, and ages.

RESULTS

The initiation of bDMARDs and MTX administration varied according to the season in a sine curve shape, with the highest numbers in May to July and the lowest numbers in November to January. The same changing pattern was observed among each bDMARD, district, gender, and age groups particularly when the number was on the higher side.

CONCLUSION

We noted an apparent seasonal change in the number of bDMARDs initiated, with a peak during spring, suggesting an exacerbation of RA in the spring in Japan. These changes are overlooked in daily practice and are only visible using big data.

Influence of Gender in Diabetes Mellitus and Its Complication

In medicine, there is growing evidence that gender differences are important and lead to variations in the pathophysiology and treatment of many diseases with traits that appear to be particularly relevant in influencing the outcomes of many morbid forms. Today, the inclusion of gender in biomedical research, to improve the scientific quality and scientific relevance of knowledge, of technology is an increasingly present element precisely due to the practical implications that derive from it. Gender differences describe the biological variability between women and men, which is, in turn, related to differences in the information contained in sex chromosomes, the specific gene expression of autosomes linked to sex, the different number and quality of sex hormones, and their different effects on systems and organs, without neglecting the fact that each of the sexes has different target organs on which these hormones act. Additionally, both genders undergo metabolic changes throughout their lives, and this is especially true for women who show more dramatic changes due to their role in reproduction. Gender differences are not only the result of our genetic makeup but are also mixed with socio-cultural habits, behaviors, and lifestyles, differences between women and men, exposure to specific environmental influences, different food and lifestyle styles or stress, or different attitude in compliance with treatments and disease prevention campaigns. Gender differences also affect behavior throughout life, and physical changes can have implications for lifestyle, social roles, and mental health. Therefore, determinism and therapeutic outcome in chronic diseases are influenced by a complex combination of biological and environmental factors, not forgetting that there are many interactions of social and biological factors in women and men. This review will address the role of gender differences in the management of various forms of diabetes and its complications considering the different biological functions of hormones, the difference in body composition, physiological differences in glucose and fat metabolism, also considering the role of the microbiota. intestinal, as well as the description of gestational diabetes linked to possible pathophysiological events typical of reproduction.

Influence of the COVID-19 pandemic on overall physician visits and telemedicine use among patients with type 1 or type 2 diabetes in Japan

BackgroundRegular visits with healthcare professionals are important for preventing serious complications in patients with diabetes. The purpose of this retrospective cohort study was to clarify whether there was any suppression of physician visits among patients with diabetes during the spread of COVID-19, in Japan and to assess whether telemedicine contributed to continued visits.MethodsWe used the JMDC Claims database which contains the monthly claims reported from July 2018 to May 2020 and included 4595 (type 1) and 123,686 (type 2) patients with diabetes.Using a difference-in-differences analysis, we estimated the changes in the monthly numbers of physician visits or telemedicine per 100 patients in April and May 2020 compared with the same months in 2019.ResultsFor patients with type 1 diabetes, the estimates for total overall physician visits were -2.53 (95% CI, -4.63 to 0.44) in April and -8.80 (-10.85 to -6.74) in May; those for telemedicine visits were 0.71 (0.47 to 0.96) in April and 0.54 (0.32 to 0.76) in May. For patients with type 2 diabetes, the estimates for overall physician visits were -2.50 (-2.95 to -2.04) in April and -3.74 (-4.16 to -3.32) in May; those for telemedicine visits were 1.13 (1.07 to 1.20) in April and 0.73 (0.68 to 0.78) in May.ConclusionsThe COVID-19 pandemic was associated with suppression of physician visits and a slight increase in the utilisation of telemedicine among patients with diabetes during April and May 2020.

The Age of Death in Japanese patients with type 2 and type 1 diabetes: A descriptive epidemiological study

This study clarified the age of death in patients with or without diabetes using the largest health insurance database in Japan. This population‐based retrospective cohort study was performed using the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) data. The ages of death between people with and without diabetes were compared. A total of 142,277,986 patients (74,488,962 women and 67,789,024 men) over 6 years, including 4,647,016 females, and 6,507,817 males with diabetes, were included. 2,786,071 females and 2,975,876 males died over 6 years, including 652,699 females and 954,655 males with diabetes. The average age of death in patients with diabetes was 2.6 years less than that of patients without diabetes. This descriptive epidemiological study illustrated the difference in age at death of patients with and without diabetes.

The Incidence of Adult-Onset Type 1 Diabetes: A Systematic Review From 32 Countries and Regions

BACKGROUND

The epidemiology of adult-onset type 1 diabetes (T1D) incidence is not well-characterized due to the historic focus on T1D as a childhood-onset disease.

PURPOSE

We assess the incidence of adult-onset (≥20 years) T1D, by country, from available data.

DATA SOURCES

A systematic review of MEDLINE, Embase, and the gray literature, through 11 May 2021, was undertaken.

STUDY SELECTION

We included all population-based studies reporting on adult-onset T1D incidence and published from 1990 onward in English.

DATA EXTRACTION

With the search we identified 1,374 references of which 46 were included for data extraction. Estimates of annual T1D incidence were allocated into broad age categories (20-39, 40-59, ≥60, or ≥20 years) as appropriate.

DATA SYNTHESIS

Overall, we observed the following patterns: 1) there is a paucity of data, particularly in low- and middle-income countries; 2) the incidence of adult-onset T1D is lowest in Asian and highest in Nordic countries; 3) adult-onset T1D is higher in men versus women; 4) it is unclear whether adult-onset T1D incidence declines with increasing age; and 5) it is unclear whether incidence of adult-onset T1D has changed over time.

LIMITATIONS

Results are generalizable to high-income countries, and misclassification of diabetes type cannot be ruled out.

CONCLUSIONS

From available data, this systematic review suggests that the incidence of T1D in adulthood is substantial and highlights the pressing need to better distinguish T1D from T2D in adults so that we may better assess and respond to the true burden of T1D in adults.

Evaluation of adrenaline auto-injector prescription profiles: A population-based, retrospective cohort study within the National Insurance Claims Database of Japan

BACKGROUND

Adrenaline is the first-line medication for managing anaphylaxis. A better understanding of prescription trends for adrenaline auto-injectors (AAIs) is important to improving patient care as well as information on health education interventions and medical guidelines. However, it has been difficult to gather comprehensive data in a sustainable manner. Thus, we aimed to investigate trends in AAI prescriptions in Japan.

METHODS

We searched the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB), a unique and comprehensive database of health insurance claims, and investigated prescriptions for AAIs for all ages (April 2017 to March 2018). We assessed the annual number of prescriptions per person as well as prescription rates per 100,000 population per year by age, sex, and geographic region.

RESULTS

A total of 88,039 subjects (56,109 males, 31,930 female) and 116,758 devices (1.33 AAIs per patient per year) were prescribed AAIs at least once a year for all ages. The prescription rate for AAIs was 69.5 per 100,000 population-years. Patients aged 0-9 years were prescribed AAIs at the rate of 278.9 per 100,000 population-years. Patients aged 0-19 years were 6.4 times more likely to be prescribed AAIs than those over 20 years of age. Males were more frequently prescribed AAIs than females in all age groups, except for those aged 20-24 years. We also evaluated differences in prescription rates by geographic region.

CONCLUSIONS

This comprehensive evaluation revealed trends in AAI prescriptions, thus helping develop preventive strategies with respect to anaphylaxis in Japan.

The Impact of Diabetes on Vascular Disease: Progress from the Perspective of Epidemics and Treatments

At present, the global incidence of diabetes has increased in countries with large populations, and the changes in developing regions are particularly worthy of attention. In the past 40 years or so, the income situation in China, India, and other countries has exploded, leading to changes in the way of life and work as well as an increase in the prevalence of diabetes. Metabolic disorders caused by diabetes can lead to secondary vascular complications, which have long-term malignant effects on the heart, kidneys, brain, and other vital organs of patients. Adequate primary prevention measures are needed to reduce the incidence of diabetic vascular complications, and more attention should be given to treatment after the disease. To this end, it is necessary to determine a standardized drug and physical therapy system and to build a more efficient and low-cost chronic disease management system.

Incidence of Diabetic Ketoacidosis Among Pediatrics With Type 1 Diabetes Prior to and During COVID-19 Pandemic: A Meta-Analysis of Observational Studies

BACKGROUND

Previous reports suggest that the Coronavirus Disease-2019 (COVID-19) pandemic might have affected incidences of diabetic ketoacidosis (DKA) and new diagnoses of type 1 diabetes. This systematic review and meta-analysis aimed to estimate the risk of DKA, including severe DKA, during the COVID-19 pandemic versus the prior-to-COVID-19 period among pediatric patients with type 1 diabetes.

METHODS

PubMed and EMBASE were searched for observational studies investigating the risk of DKA among pediatric patients with type 1 diabetes during the COVID-19 pandemic and the prior-to-COVID-19 period. A random meta-analysis model was performed to estimate the relative risk of DKA during the COVID-19 pandemic compared to before the pandemic. Subgroup analyses were conducted based on the type 1 diabetes status, established or newly diagnosed. In addition, sensitivity analysis was conducted for studies that reported results from adjusted analysis for potential confounders using fixed effect model.

RESULTS

A total of 20 observational studies reported the risk of DKA, of which 18 reported the risk of severe DKA. The risks of DKA and severe DKA were 35% (RR 1.35, 95%CI 1.2-1.53, I² = 71%) and 76% (RR 1.76, 95%CI 1.33-2.33, I^{2 =} 44%) higher in the during-COVID-19 group compared to the prior-to-COVID-19 group, respectively. Among patients with newly diagnosed type 1 diabetes, the risk of DKA was 44% higher for the during-COVID-19 group compared to the prior-to-COVID-19 group (RR 1.44, 95%CI 1.26-1.65; I² = 64%). Only two studies reported the risk of DKA among patients with established type 1 diabetes and the cumulative risk was not statistically significant. In the sensitivity analysis, four studies reported an adjusted odds ratio (aOR) of the risk of DKA during COVID-19 compared to the prior-to-COVID-19 period. The fixed estimate from the meta-analysis found an increase in the risk of DKA in the during-COVID-19 group compared to the prior-to-COVID-19 group (aOR 2.04, 95%CI 1.66-2.50).

CONCLUSIONS

This study showed that DKA risk, especially the risk of severe DKA, has increased significantly during the pandemic. Healthcare systems must be aware and prepared for such an increase in DKA cases and take all necessary measures to prevent future spikes during the pandemic.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=272775, identifier PROSPERO [CRD42021272775].

Prevalence of Autoimmune Disease in Patients with Eosinophilic Esophagitis: A Cross-sectional Study of Three Hospitals in Japan

Objective Recent studies have found higher rates of autoimmune diseases, such as celiac disease, Crohn's disease, and ulcerative colitis, in patients with eosinophilic esophagitis (EoE) than in the general population. This study investigated the concomitant rate of autoimmune disease among Japanese patients with EoE and evaluated the clinicopathological characteristics of EoE patients with autoimmune disease. Methods The medical records of patients diagnosed with EoE between April 1, 2016, and June 30, 2020, were reviewed. We analyzed the concomitant rate of autoimmune diseases in patients with EoE and compared the clinical and histological differences between patients with and without autoimmune disease. Results Sixty-four patients with EoE were enrolled. Of them, 1 had ulcerative colitis (1.6%), 1 had autoimmune polyendocrine syndrome type 2 (1.6%), and 6 had endometriosis (28.5% of women, 44.4% of reproductive-aged women). No significant differences in the clinical course or histological findings were found between EoE patients with and without autoimmune diseases. No complications, including stenosis, were seen in EoE with autoimmune disease, and most patients with EoE and autoimmune diseases were responsive to proton pump inhibitors (PPIs). Conclusion In this study, 8 out of 64 patients with EoE had an autoimmune-related disease, including ulcerative colitis (n=1, 1.6%), autoimmune polyendocrine syndrome type 2 (n=1, 1.6%), or endometriosis (n=6, 44.4% of women of reproductive age), which is higher than that previously reported in the general population. Further investigations are required to clarify the relationship between EoE and autoimmune diseases.

Association between influenza and the incidence rate of new-onset type 1 diabetes in Japan

AIM

This study aimed to determine whether there is an association between influenza and new-onset type 1 diabetes.

MATERIALS AND METHODS

This population-based retrospective cohort study used data from the National Database of Health Insurance Claims and Specific Health Check-ups of Japan. Influenza was defined based on drug prescriptions and the onset of type 1 diabetes was defined using specific medical codes indicating a diagnosis of type 1 diabetes. The incidence rate ratio of new-onset type 1 diabetes within 180 days after an influenza diagnosis was calculated and it was compared with that at other times using Poisson regression and generalized estimating equations. Sensitivity analyses were performed to confirm the robustness of this finding.

RESULTS

The data of 10,400 patients with new-onset type 1 diabetes were analyzed, including 2,196 (952 male 1,244 female) patients diagnosed with influenza between 1 September 2014 and 31 August 2017. Although only patients with type 1 diabetes were included, adjusted analysis showed that individuals had a 1.3-fold (95% confidence interval: 1.15-1.46) higher risk of developing type 1 diabetes in the first 180 days after influenza diagnosis than that at other times.

CONCLUSIONS

In this Japanese population-based cohort, the risk of new-onset type 1 diabetes may increase after the diagnosis of influenza. These results, which must be confirmed in other populations, suggest that influenza may be a causal factor for new-onset type 1 diabetes. The molecular mechanisms underlying the potential etiological relationship between influenza and type 1 diabetes should be elucidated.

Appropriate definition of diabetes using an administrative database: A cross-sectional cohort validation study

Aims/Introduction

The purpose of the present study was to quantify errors in the diagnosis of diabetes for use in the national database, using a sufficient population size.

Materials and methods

A claims database constructed by the JMDC (Tokyo, Japan), using standardized disease classifications and anonymous record linkage, was used in this validation study. We included patients with health insurance claims data from April 2005 to March 2019 in the JMDC claims database. We excluded patients without a record of specific health checkups in Japan. Sample size calculation was based on a 5% prevalence of diabetes and 0.4% absolute accuracy (i.e., 1,250,000 individuals), to calculate the sensitivity, specificity, positive predictive value and negative predictive value.

Results

In total, 2,999,152 patients were included in this study, of which 165,515 were classified as having diabetes based on specific health checkups (validation cohort prevalence of 5.5%). The newly devised algorithm had three elements – the diagnosis‐related codes for diabetes without suspected flag, the medication codes for diabetes and then these two codes on the same record – and yielded a sensitivity of 74.6%, positive predictive value of 88.4% and Kappa Index of 0.80 (the highest values).

Conclusions

In future claims database studies, our validated algorithms will be useful as diagnostic criteria for diabetes.