Takehiro Sugiyama

Objective: Excessive salt intake affects blood pressure. Thus, monitoring of salt intake is vital in the aging population. In this study, we examined the impact of salt intake reduction on medical expenditure for hypertension in Japan. Methods: System dynamics models for Japan and its 47 prefectures were developed using sub-models of salt intake, population, hypertension, and treatment costs. Co-flows of foods with high and low salt content and people with high and low salt intakes were built to calculate the daily salt intake. Aging chains of 10-year age groups from 40 to 79 years were built by sex for the population and people with hypertension (PwH). The outpatient treatment costs for hypertension were also calculated. The model parameters were calibrated using national statistics from 2012 to 2023, and prefectural models were developed to address the gaps in the national data for 2012. The simulated changes were compared across scenarios. Results: In the base run from 2012 to 2040, a reduction of 46.3% of high-salt foods and 33.1% of people with high salt intake would make a 13.9% reduction in daily salt intake from 10.1 g/day to 8.7 g/day. When salt intake is reduced to 6.9 g/day in 2040, PwH and treatment costs decrease by 2.3% and 2.0% in men and by 8.8% and 8.3% in women, respectively. The prefectural models exhibited the simulated changes. Conclusions: Our models suggest that reducing salt intake will lead to a decrease in the number of PwH and outpatient treatment costs by 2040.

Evidence-based policymaking increasingly demands integrating real-world data with patient perspectives. However, a methodological gap exists: administrative claims data provide comprehensive coverage but lack subjective insights, whereas patient experience surveys frequently experience selection bias owing to the lack of reliable sampling frames. This study introduces Claims-Based Enumeration Sampling (CBES), a methodology utilizing administrative claims data as a sampling frame to substitute for clinical registries.By linking survey responses with claims data at the individual level, CBES facilitates the calculation of sampling probabilities and the application of weighting for ensuring representativeness. We demonstrate the practical feasibility of this design through a case study conducted in Tsukuba City, Japan. Targeting National Health Insurance beneficiaries with diabetes, the survey was implemented as an insurer-commissioned administrative operation, successfully overcoming privacy- and data access-related legal hurdles. The resulting dataset revealed crucial insights into patient stigma and socioeconomic disparities, factors invisible to claims analysis alone.This study discusses the theoretical framework, statistical advantages, and legal solutions related to CBES. We conclude that CBES provides a robust and scalable alternative to conventional methods, empowering policymakers to capture the “silent voices” of patients and advancing patient-centered healthcare policy.

Aims/Introduction: We examined the differences in diabetes care between public assistance recipients (PARs), exempt from medical costs and guaranteed a minimum income, and the National Health Insurance (NHI) beneficiaries, covering non‐employed and self‐employed individuals with some cost sharing in Japan. Materials and Methods: This observational study used claims data from a Japanese municipality (April 2017–March 2022) to identify individuals aged 20–68 with type 2 diabetes on antidiabetic medications. We analyzed care processes annually and cross‐sectionally, focusing on tests, medications, and medical costs, and followed health outcomes (hypoglycemia and hospitalization) monthly and longitudinally. Multivariable Poisson regression models estimate the risk ratios for binary care processes, and a gamma regression model analyzes medical costs as continuous variables. Health outcome incidence rate ratios were assessed using multivariable Poisson regression, with the observation period as an offset. Results: We included cross‐sectional data from 11,385, 11,566, and 9,943 people (2018–2020) and longitudinal data from 18,655 individuals. In the analysis considering the whole periods, PARs were more likely to receive annual eye examinations (adjusted risk ratio 1.15, 95% confidence interval [CI] 1.08–1.22), use sodium‐glucose cotransporter‐2 inhibitors (1.22, 1.13–1.31), and use glucagon‐like peptide‐1 receptor agonists (1.63, 1.41–1.90). The total (1.16, 1.09–1.23) and outpatient medical costs (1.31, 1.24–1.38) were higher, whereas the inpatient costs (0.85, 0.77–0.94) were lower for PARs. Hypoglycemia incidence was also higher (adjusted incidence rate ratio 2.21, 95% CI 1.38–3.54). Conclusions: Public assistance might improve the diabetes care process, but not fully health outcomes. These findings suggest additional supports for PARs and further research for NHI beneficiaries in poverty.

Aims: Clinical inertia, the failure to intensify treatment despite unmet glycemic goals, is a key factor in poor glycemic management for type 2 diabetes. No studies have defined clinical inertia based on HbA1c trends. In this study, we aimed to assess treatment intensification according to HbA1c trends. Materials and methods: We analyzed data from the Japan Diabetes Comprehensive Database Project based on an Advanced Electronic Medical Record System (J‐DREAMS) between 2016 and 2023. Eligible patients with type 2 diabetes had (1) unchanged prescriptions for the past 90 days; (2) two consecutive consultations within 90 days; and (3) HbA1c levels ≥7%, or ≥7.5%, for patients aged ≥65 years at both consultations. Treatment intensification was defined as an addition or increased dose or switch in antidiabetic medications, inclusive of insulin, at the second consultation. Moreover, factors associated with treatment intensification were assessed. Results: Of the 5,683 patients, 1,130 (19.9%) received intensified treatment at the second consultation. Intensification occurred more frequently with higher HbA1c levels or worsening HbA1c trends. However, treatments were not intensified in approximately 50% of the patients, with HbA1c levels >8% or a worsening of >1%. Predictive factors included the HbA1c levels at the second consultation, changes in the HbA1c levels between the first and second consultations, the number of oral hypoglycemic medications, and the use of sulfonylureas or glinides. Conclusions: Physicians should consider HbA1c trends to guide treatment intensification when HbA1c levels exceed target thresholds. Clinical inertia remains an important issue in diabetes management.

Aim: Physician‐led home‐visit care has become essential in the super‐aged society of Japan. To develop region‐specific service systems, understanding regional differences in patient profiles is essential. This study aimed to describe regional differences in patient characteristics, service utilization, and outcomes, and to assess the associations between regional healthcare resources and patient outcomes. Methods: This retrospective study used linked data from the National Database of Health Insurance Claims and Specific Health Checkups and the Japanese Long‐term Care Database (April 2020–March 2021). Patients aged ≥ 65 years receiving regular physician‐led home visits in October 2020 were included. Analyses were conducted by prefecture and region. Associations between regional healthcare resources and patient outcomes were assessed using Spearman's correlation coefficients ( ρ ). Results: Among 337 863 patients, regional variations were observed. Western Japan had a higher prevalence of cancer, heart disease, respiratory disease, and orthopedic disorders, whereas Tohoku showed the highest rates of high care‐need levels and home nursing utilization. Hospitalization risk was highest in western Japan, whereas in‐home deaths were more frequent in eastern Japan. Hospital bed density was positively correlated with hospitalization risk ( ρ = 0.62) and negatively with 6‐month mortality risk ( ρ = −0.44). Utilization of enhanced home care support clinics/hospitals was moderately associated with higher in‐home death risks ( ρ = 0.49). Conclusions: Substantial regional differences exist in patient characteristics, service utilization, and outcomes among older adults receiving physician‐led home‐visit care. Healthcare resources were strongly associated with hospitalization and end‐of‐life care, highlighting the need for region‐specific strategies to optimize healthcare delivery and resource allocation for the super‐aged society of Japan.

Aims/Introduction: Investigating the causes of death in individuals with diabetes compared with those without is essential for understanding diabetes care. However, methods for identifying individuals with diabetes within populations vary. We conducted a comparison of these groups under identical conditions, analyzing differences in causes and age at death, and assessing how different identification methods influence these outcomes.Materials and Methods: This study used the clinical records of inpatients who died at the National Center for Global Health and Medicine from September 1, 2010, to December 31, 2020. Individuals with or without diabetes were defined using prescriptions and laboratory data. The cause of death was determined by the name of the primary illness provided by the attending physician at the time of death. Individuals with diabetes were stratified by different definitions, and their age at death was compared.Results: In Individuals with diabetes, males accounted for 67.6%, and in those without diabetes, 57.0%. The mean age at death was 75.0 ± 11.8 and 73.8 ± 16.0 years, respectively. Malignant neoplasia was the most common cause of death in both groups, with a higher frequency in individuals with diabetes (36.9% vs 31.0%). Age at death of individuals with diabetes differed by up to 1.5 years, depending on the definitions.Conclusions: Direct comparisons suggested that malignant neoplasia was the leading cause of death, and individuals with diabetes had a higher mean age at death. The method used to identify diabetes influenced these outcomes, emphasizing the importance of careful consideration in mortality studies.

Aims: This study aimed to assess the relationship between individuals' recognition of ophthalmology consultation recommendations, their knowledge of the recommended frequency of diabetic retinopathy screening, and the likelihood of undergoing fundus examinations. Materials and Methods: This cross‐sectional secondary analysis linked claims and health checkup data to a questionnaire survey. Questionnaires were distributed to randomly sampled National Health Insurance beneficiaries in Tsukuba City, using data from claims and health checkups. Weighting was applied based on sample extraction and response rates. We calculated the proportions of fundus examinations and knowledge of screening frequency according to the recognition of ophthalmology consultation recommendations. The association between visits to medical facilities with diabetes specialists and diabetic retinopathy screening was also examined. Results: Among 290 participants, 47.6% recognized ophthalmology consultation recommendations. Those who recognized these recommendations had better knowledge of the screening frequency (93.4% vs. 49.6%) and were more likely to undergo fundus examinations (72.9% vs. 30.1%; adjusted risk ratio 2.36; 95% CI, 1.65–3.38). Participants who visited medical facilities with diabetes specialists were more likely to recognize recommendations, have knowledge of screening frequency, and undergo fundus examinations. Conclusions: Recognition of ophthalmology consultation recommendations was associated with better knowledge of screening frequency and higher participation in fundus examinations. Increasing awareness through healthcare provider recommendations may improve diabetic retinopathy screening rates, highlighting the need for targeted interventions to promote eye care among individuals with diabetes.

Objectives: Strengthening the research workforce is essential to safeguard public health and human lives. This study examined the associations between work hours and perceived performance appraisal, and the intention to leave the medical research workforce. Methods: This cross-sectional study used data collected from medical researchers between December 2022 and January 2023. The questionnaire was distributed to participants via all 141 societies of the Japanese Association of Medical Sciences. Weekly work hours were self-reported using 10 response options. Perceived appraisal of research performance at work was assessed using 6 response options and dichotomized into inappropriately appraised (slightly disagree/totally disagree) and the rest. Intention to leave the research workforce was also self-reported and dichotomized. We calculated multivariable-adjusted odds ratios (aORs) for intention to leave, according to work hours and perceived appraisal. Results: Of 3139 participants (852 women), most (n = 686) worked 60-79 hours weekly. One in four (n = 745) felt inappropriately appraised, and 11% (n = 356) intended to leave. A U-shaped association was observed between work hours and intention to leave (aOR: 2.05; 95% CI, 1.12-3.73, for weekly working 100 hours or longer), although the quadratic trend was not significant (P = .15). The inappropriately appraised group had a 3.6 times (95% CI, 2.81-4.58) higher OR of intending to leave compared with their appropriately appraised counterparts. Conclusions: The results suggest that researchers who work long hours and feel inappropriately appraised are more likely to consider leaving the medical research workforce.