Regional variance in patterns of prescriptions for chronic kidney disease in Japan

Clinical epidemiology of the endoscopic, laparoscopic, and surgical resection of malignant gastric tumors in Japan, 2014-2021: a retrospective study using open data from a national claims database

BACKGROUND

Gastric cancer is a common malignancy with a high incidence in East Asia. Gastric resection ranges from endoscopic resection to open total gastrectomy. However, nationwide data are lacking.

METHODS

This observational study analyzed data from the publicly accessible National Database of Health Insurance Claims and Specific Health Checkups, which includes most national health insurance claims data in Japan. Trends in the types of resection performed for malignant gastric tumors between 2014 and 2021, patients' age and sex distributions, and regional disparities were investigated.

RESULTS

The annual number of resections was highest in 2015 (109,000) and lowest in 2020 (90,000) after the COVID-19 pandemic. The proportion of endoscopic resections increased from 47% in 2014 to 57% in 2021 while that of total gastrectomies decreased from 17 to 10%. In 2021, 70% of patients who underwent resection were men. That year, 83.8% of all patients who underwent any type of gastric resection and 87.1% of those who underwent endoscopic submucosal dissection were aged ≥ 65 years. The annual incidence of gastric resection per million population was highest in Tottori (n = 1236) and lowest in Okinawa (n = 251). The proportion of endoscopic resections was highest in Miyagi (66%) and lowest in Aichi (45%) and that of open surgery was highest in Aomori (36%) and lowest in Wakayama (5%).

CONCLUSIONS

Gastric malignancy is increasingly treated by endoscopic submucosal dissection rather than open total gastrectomy. However, regional disparities remain in resection type. Standardization of treatment and a more even distribution of specialists are needed.

Prescription of anti-influenza drugs in Japan, 2014-2020: A retrospective study using open data from the national claims database

BACKGROUND

Both physicians and patients are proactive towards managing seasonal influenza in Japan and six drugs are approved. Although many countries have national influenza surveillance systems, data on nationwide prescription practices of anti-influenza drugs are lacking. Therefore, we aimed to clarify the status of anti-influenza drug use in Japan by analyzing real-world data.

METHODS

This retrospective study analyzed open data from the National Database of Health Insurance Claims and Specific Health Checkups, which covers most claims data from national health insurance. We estimated the annual number of patients prescribed anti-influenza drugs, which drugs they were prescribed, the patients' age and sex distribution, drug costs, and regional disparities for the period 2014-2020.

RESULTS

For 2014-2019, an estimated 6.7-13.4 million patients per year were prescribed anti-influenza drugs, with an annual cost of 22.3-48.0 billion JPY (Japanese Yen). In addition, 21.1-32.0 million rapid antigen tests were performed at a cost of 30.1-47.1 billion JPY. In 2017, laninamivir was the most frequently prescribed anti-influenza drug (48%), followed by oseltamivir (36%), while in 2018, the newly introduced baloxavir accounted for 40.8% of prescriptions. After the emergence of COVID-19, the estimated number of patients prescribed anti-influenza drugs in 2020 dropped to just 14,000. In 2018, 37.6% of prescriptions were for patients aged < 20 years compared with 12.2% for those aged ≥ 65 years. Prescriptions for inpatients accounted for 1.1%, and the proportion of prescriptions for inpatients increased with age, with men were more likely than women to be prescribed anti-influenza drugs while hospitalized.

CONCLUSIONS

Based on our clarification of how influenza is clinically managed in Japan, future work should evaluate the clinical and economic aspects of proactively prescribing anti-influenza drugs.

Regional Variation in the Use of Percutaneous Kidney Biopsy in Japan

INTRODUCTION

The regional variation in the use of percutaneous kidney biopsy in Japan remains unknown. There are several large datasets of kidney biopsies in Japan, but an exhaustive survey of kidney biopsies is lacking.

METHODS

We analyzed insurance claims for percutaneous kidney biopsies registered in the National Database of Health Insurance Claims and Specific Health Checkups of Japan, which is the closest to a complete dataset of kidney biopsies performed in Japan. In combination with other nationwide survey results, the number of inpatient percutaneous kidney biopsies per population in each prefecture was calculated. Factors associated with the frequency of percutaneous kidney biopsies were also explored.

RESULTS

The database contained 22,419 health insurance claims for percutaneous kidney biopsy in the fiscal year 2020. The frequency of inpatient percutaneous kidney biopsies could be up to 4.8 times as frequent in one prefecture than in another, even after adjusting for age and sex. The frequency of inpatient percutaneous kidney biopsies showed a positive correlation with the number of annual kidney transplants and patients on peritoneal dialysis per population and a weak negative correlation with the prevalence of reduced kidney function in the population aged 40-74 years.

CONCLUSION

We found a large regional variation in the frequency of inpatient percutaneous kidney biopsies. Kidney transplants and peritoneal dialysis might be offered more frequently in regions with a higher frequency of kidney biopsy. This is the first dataset that shows more than 20,000 kidney biopsies were performed per year in Japan, as of 2020.

Chronic kidney disease prevalence and awareness in middle age and young old: Regional comparative study in Japan

AIM

Patients with chronic kidney disease are not aware of the illness because of its asymptomatic nature, but the association of disease progression and awareness in general population has not been sufficiently analysed on a large scale.

METHODS

We analysed the nationwide annual specific health checkup covering more than a half of the overall population at aged 40-74 in Japan, approximately 29.4 million people as of 2018, in combination with parameters to represent regional characteristics.

RESULTS

The rate of the examinees with kidney dysfunction, an estimated glomerular filtration rate of <45 mL/min/1.73 m² , was 1.0%, while that of examinees with of dipstick proteinuria ≥ (+) was 3.7%. Next, we conducted a regional comparative study on 335 medical administrative areas divided in the country. The regional rate of examinees aged 65-74 over the total examinees was positively correlated with the prevalence of kidney dysfunction (r = 0.72, p < .0001). Additionally, the mean rate of examinees aware of their 'chronic kidney failure' was 0.6%, and the awareness rate was correlated with the prevalence of both kidney dysfunction (r = 0.36, p < .001) and positive dipstick proteinuria (r = 0.31, p < .001) in those aged 65-74 at the regional level. Association of nephrology care resources with the prevalence or awareness was unclear at the regional level.

CONCLUSION

We found a regional association of chronic kidney disease prevalence and awareness in a recent young old population in Japan. Further studies are needed to evaluate the patient screen and referral at the individual level.

Analysis of regional differences in the amount of hypnotic and anxiolytic prescriptions in Japan using nationwide claims data

BACKGROUND

In Japan, there has been no investigation of regional differences in the number or amount of prescriptions of anxiolytics or hypnotics. Attributes related to the high amount of prescriptions for these drugs are unknown. We investigated recent trends and regional differences in the amount of prescriptions of hypnotics and anxiolytics in Japan and identified factors associated with these regional differences.

METHODS

The National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) Open data from 2015 to 2018 were used. We calculated diazepam-equivalent doses (mg) for each drug and the total amount of prescriptions per capita for hypnotics and anxiolytics by sex and age. In addition, we calculated the standardized claim ratio (SCR) of the amount of prescriptions by prefecture. We investigated factors associated with regional differences in the SCRs of hypnotics and anxiolytics using the prefectures' medical, socioeconomic, and physical characteristics by an ecological study using a linear mixed-effects model.

RESULTS

The amount of prescriptions of hypnotics and anxiolytics, specifically, the amount of prescriptions of benzodiazepine receptor agonists (BZRAs), decreased in many of the adult age groups from 2015 to 2018. The regression analysis revealed that the number of medical clinics per capita, the number of public assistance recipients per capita, the proportion of persons whose HbA1c ≥ 6.5%, and the proportion of persons whose BMI ≥25 kg/m2 were positively and significantly associated with the SCR of hypnosis. In contrast, the number of public assistance recipients per capita and the proportion of persons whose BMI ≥25 kg/m2 were positively and significantly associated with the SCR of anxiolytics.

CONCLUSIONS

Factors associated with prescription amount of hypnotics and anxiolytics were revealed in this study, and a further study is needed for investigating causal relationships between the prescriptions amount and the associated factors using individual data.

Regional Distribution of Cardiologists and Prescription Patterns of Sodium-Glucose Transporter-2 Inhibitors in Japan

The clinical evidence is accumulating since 2015 that anti-diabetic sodium-glucose cotransporter 2 (SGLT2) inhibitors have the beneficial effect of cardiovascular and, recently, renal protection. Although it is not well analyzed how the transfer of this new evidence into daily practice has expedited, we hypothesize that the recent usage of the drugs is positively associated with several certified cardiologists in each region.The 2016 annual and 2016-2017 increased number of SGLT2 inhibitor tablets, based on the National Database of Health Insurance Claims and Specific Health Checkups of Japan, were divided by the estimated number of patients with type 2 diabetes mellitus for each of the 47 prefectures. Then, regression analyses were performed to investigate the potential association of the number of certified cardiologists with the drug prescription.The 2016 prescription of ipragliflozin, dapagliflozin, luseogliflozin, canagliflozin, and empagliflozin was 2.7- to 4.4-fold different between prefectures. The 2016-2017 increased prescription volume also varied among prefectures by as large as 7.3-fold for ipragliflozin. Regression analysis revealed that the annual and increased prescription volume of all the SGLT2 inhibitors except luseogliflozin were higher in regions with more certified cardiologists (P < 0.05), even after adjusting for regional parameters.In conclusion, the regional number of certified cardiologists was positively associated with a 2016 annual of and 2016-2017 increase in SGLT2 inhibitor prescription amount, implying an early adopter role of clinical experts in healthcare delivery.

Regional Variance of the Early Use of Tolvaptan for Autosomal Dominant Polycystic Kidney Disease

Background

The development and prompt dissemination of the first drug against a particular disease can contribute to improvements in national health status and medical economy end points and are assumedly affected by socioeconomic factors that have yet to be analyzed. Tolvaptan, a vasopressin receptor 2 antagonist, was developed to treat hyponatremia, congestive heart failure, and cirrhosis ascites, although the approved indications may differ among countries. In Japan, high-dose tolvaptan tablets were approved as the first drug for autosomal dominant polycystic kidney disease (ADPKD) in 2014. This study aimed to better understand the factors that influence the total number of regional prescriptions of tolvaptan for ADPKD since its launch.

Methods

The National Database of Health Insurance Claims and Specific Health Checkups of Japan Open Data was used as a national claim-based database. In each of the 47 prefectures in Japan, the total prescribed number of 30 mg tolvaptan tablets between 2015 and 2017 was examined. The parameters explaining the prescription variation among regions were then examined by correlation analysis.

Results

Prescriptions for high-dose tolvaptan increased substantially 2 years after the drug's approval; however, the increase differed by approximately 21-fold between regions. Population density was positively associated with prescribed 30 mg tolvaptan tablets per 1000 population in 2015 (r=0.47, P<0.001). In addition, the increase in prescribed number of tablets per 1000 population was correlated with population density in 2016-2017 (r=0.30, P=0.04).

Conclusions

This macro perspective analysis revealed an urban-rural inequity in prescriptions for the newly approved drug for ADPKD. Further studies are needed to elucidate the factors affecting the geographic variation.

Uremic Sarcopenia: Clinical Evidence and Basic Experimental Approach

Sustained physical activity extends healthy life years while a lower activity due to sarcopenia can reduce them. Sarcopenia is defined as a decrease in skeletal muscle mass and strength due not only to aging, but also from a variety of debilitating chronic illnesses such as cancer and heart failure. Patients with chronic kidney disease (CKD), who tend to be cachexic and in frail health, may develop uremic sarcopenia or uremic myopathy due to an imbalance between muscle protein synthesis and catabolism. Here, we review clinical evidence indicating reduced physical activity as renal function deteriorates and explore evidence-supported therapeutic options focusing on nutrition and physical training. In addition, although sarcopenia is a clinical concept and difficult to recapitulate in basic research, several in vivo approaches have been attempted, such as rodent subtotal nephrectomy representing both renal dysfunction and muscle weakness. This review highlights molecular mechanisms and promising interventions for uremic sarcopenia that were revealed through basic research. Extensive study is still needed to cast light on the many aspects of locomotive organ impairments in CKD and explore the ways that diet and exercise therapies can improve both outcomes and quality of life at every level.

Regional variance in the use of urine dipstick test for outpatients in Japan

AIM

The urine dipstick is a simple diagnostic module for detecting proteinuria, haematuria and glycosuria and is favourably accepted in East Asia despite debates regarding its accuracy and target population, claiming that quantitative tests for a high-risk cohort should be more cost-effective. However, the current status of utilizing this test in these countries is not widely known due to lack of extensive data. We aimed to clarify the current nationwide and regional status of utilization of the urine dipstick test in an outpatient care setting and to determine the regional factors associated with adoption of this method.

METHODS

This cross-sectional study used openly accessible data from the national claim database that included the health insurance claims data of the Japanese population in 2017.

RESULTS

In total, 67 125 386 urine dipstick tests were performed compared with 1 862 700 quantitative urine protein tests and 17 544 949 urine sediment microscopy tests. Dipstick tests were employed principally for those who are >65 years old (60.3%) and, although the male population (52.5%) is generally larger, the female population is larger in age of 15 to 39 years and >85 years. Multivariate analysis with several regional parameters revealed that the test was performed more commonly in the areas that accommodate greater elderly population (P < .01).

CONCLUSION

Despite a heated dispute, the urine dipstick test is performed even more frequently than the quantitative biochemical or microscopic sediment tests, especially in regions holding the larger elderly population, which suggests that the test forms a part of geriatric medical care.