Association between the size of healthcare facilities and the intensity of hypertension therapy: a cross-sectional comparison of prescription data from insurance claims data

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.

Use of fixed-dose combination antihypertensives in Germany between 2016 and 2020: an example of guideline inertia

BACKGROUND

The 2018 European Society of Cardiology (ESC)/European Society of Hypertension (ESH) guidelines for the management of hypertension highlight the importance of fixed-dose combinations (FDC) for the treatment of hypertension and recommend initial single-pill combination therapy in almost all patients. However, data on the implementation of these recommendations in clinical practice are scarce.

METHODS

Data from the German Institute for Drug Use Evaluation (DAPI) were analyzed and extrapolated accounting for approximately 88% of Germany's population (approximately 73.3 million subjects). All antihypertensive (AHT) FDC products available on the German market were included in the analyses. We examined the time course of dispensed packages between January 2016 and December 2020.

RESULTS

FDCs accounted for 15.4% of all AHT in 2016 and for 10.9% in 2020. While dispensing of all AHT increased slightly from year to year (2016: 143.8 million, 2020: 153.2 million packs), dispensing of FDCs decreased from 22.2 million (2016) to 16.6 million (2020) packs. Dispensing of FDCs containing hydrochlorothiazide (HCT) declined considerably from 2016 to 2020 (Q1 2016: 4.65 million, Q4 2020: 3.13 million packs). Accordingly, the proportion of HCT-containing combinations in all FDCs decreased from 85.3 to 74.2% from Q1 2016 to Q4 2020. Patients younger than 80 years were prescribed FDCs more frequently (14.6% of all AHT, based on the entire evaluation period) than patients 80 years and older (10.0%). In both age groups, this proportion decreased continuously over time.

CONCLUSIONS

Almost 2 years following the release of the 2018 ESC/ESH guidelines, only 10.9% of the prescribed packs of antihypertensive drugs in 2020 were FDC products, documenting underutilization of current guideline recommendations on pharmacotherapy in hypertension. Structured programs to evidence-based decision support are required to improve guideline inertia and patient outcomes, eventually.

Calcium channel blocker in patients with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is involved in a progressive deterioration in renal function over the years and is now a global public health problem. Currently, reducing the number of patients progressing to end-stage renal failure is urgently necessary. Hypertension and CKD interact with each other, and good control of blood pressure (BP) can improve CKD patients' prognosis. With the current global trend for more strict BP control, the importance of BP management and the need for medication to achieve this strict goal are increasing. Calcium channel blockers (CCBs), which target voltage-dependent calcium channels, are frequently used in combination with renin-angiotensin-aldosterone system inhibitors for CKD patients because of their strong BP-lowering properties and relatively few adverse side effects. Calcium channels have several subtypes, including L, N, T, P/Q, and R, and three types of CCBs, L-type CCBs, L-/T-type CCBs, and L-/N-type CCBs, that are available. Nowadays, the new functions and effects of the CCBs are being elucidated.

CONCLUSION

We should use different types of CCBs properly depending on their pharmacological effects, such as the strength of antihypertensive effects and the organ protection effects, taking into account the pathophysiology of the patients. In this article, the role and the use of CCBs in CKD patients are reviewed.

Nationwide incidence of central retinal artery occlusion in Japan: an exploratory descriptive study using the National Database of Health Insurance Claims (2011-2015)

AIMS

The latest evidence in the incidence of central retinal artery occlusion (CRAO) is needed to support the development of novel treatments as orphan drugs. However, up-to-date information on the incidence of CRAO in the ageing or aged population is limited. We aimed to investigate the nationwide epidemiological and clinical characteristics of CRAO in Japan, using nationwide health insurance claims data.

METHODS

We analysed a total of 16 069 762 claims data in the sampling dataset of the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB), which is the nationwide health insurance claims database of 127 million whole Japanese individuals. CRAO was identified using the International Classification of Diseases 10th edition diagnostic code H34.1. The crude incidence rates and age-standardised incidence rates of CRAO, according to the standard age-structure population of the WHO, were calculated.

RESULTS

The crude incidence rate of CRAO in Japan was 5.84 (95% CI, 5.71 to 5.97) per 100 000 person-years. With respect to the sex-related incidence, the rate was higher 1.40 times in men than in women (6.85 (95% CI, 6.65 to 7.06) vs 4.88 (95% CI, 4.71 to 5.05), p<0.001). The age-standardised incidence rate was 2.53 (95% CI, 2.29 to 2.76) per 100 000 person-years.

CONCLUSIONS

The crude incidence rate of CRAO was higher in Japan than in other countries, as reported previously, reflecting the Japanese population structure as a super-aged society. These findings can be helpful for the development of appropriate healthcare policies to address the increasing incidence of CRAO with the ageing population.