Relationship between antihypertensive drug use and number of people with high blood pressure in FY 2018: a descriptive epidemiological study based on the National Database of Health Insurance Claims and Specific Health Checkups of Japan open data

In most countries barring Japan, antihypertensive drug use has been reported using the defined daily doses/1000 inhabitants/day (DID). Although DID has been shown to allow for the assessment of the number of patients treated with a particular drug, the relationship between DID and the number of patients with hypertension has not been clarified. This study aimed to clarify the relationship between antihypertensive drug use and the number of people with high blood pressure based on the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) open data. DID was calculated by extracting the use of oral antihypertensive drugs from outpatient prescriptions in the NDB Open Data in FY 2018. The number of people with high blood pressure was calculated using the number of enrollees in each sex-age group for systolic and diastolic blood pressure in the 40-74 years age group. The correlation between the DID of antihypertensive drugs and the number of people with high blood pressure by sex and age class was evaluated using Spearman's rank correlation coefficient. The use of antihypertensive drugs increased with age in both men and women. Furthermore, in both sexes, dihydropyridine derivatives, calcium antagonists, and angiotensin II receptor blockers were the main drugs used from the age of 20 years onward. In addition, a very strong positive correlation was found between the number of people with high systolic blood pressure and DID in both sexes (men: r = 1, P 0.05). To our knowledge, this study is the first to investigate the use of oral antihypertensive drugs in outpatient settings in Japan. In addition, the DID of antihypertensive drugs can be used as an alternative indicator of the number of people with high systolic blood pressure.