Impact of hypertension on medical economics: A 10-year follow-up study of national health insurance in Shiga, Japan

Association between anthropometric indices and 5-year hypertension incidence in the general Japanese population

No existing reports demonstrate the association between anthropometric indices (body mass index, waist circumference, body roundness index, a body shape index) and hypertension according to sex and age in the general Japanese population. This retrospective analysis involved individuals aged 30-69 years who underwent annual medical checkups at Kagoshima Koseiren Hospital in 2005-2019, and who did not meet hypertension criteria at baseline. The outcome was hypertension incidence after 5 years, and its association with baseline anthropometric indices was evaluated using multivariable logistic regression analysis by sex and age. In 41,902 participants (age 52.3 ± 10.2 years, 47.7% men), 7622 individuals (18.2%) developed hypertension after 5 years. Body mass index, waist circumference, and body roundness index were significantly associated with the development of hypertension in both men and women across all age categories from 30 s to 60 s. In the population with a body mass index <25 kg/m2, waist circumference and body roundness index were significantly associated with hypertension after 5 years. A body shape index was significantly associated with the development of hypertension in men in their 40 s and 50 s but not in women of any age group. The area under the curve values were lower for a body shape index than for body mass index, waist circumference, and body roundness index in both men and women of all age groups. A body shape index was not a stronger indicator for 5-year hypertension incidence than body mass index, waist circumference, or body roundness index in both men and women across age groups from their 30s-60 s. The results of this study will help to more efficiently identify populations at high risk of developing hypertension and provide preventive interventions. A total of 41,902 participants from health checkup programs were stratified by gender and age to investigate the association between baseline anthropometric indices and hypertension incidence over a 5-year period. BMI, WC, and BRI were almost equally effective and showed a better association with risk of developing hypertension in women and young adults compared to men and old adults. Conversely, ABSI showed no greater association than BMI or WC in any age group in both men and women. ABSI, a body shape index; AUC, area under the curve from receiver operating characteristic curve analysis; BMI, body mass index; BRI, body roundness index; WC, waist circumference.

The associations of multimorbidity with the sum of annual medical and long-term care expenditures in Japan

BACKGROUND

The occurrence of multimorbidity (i.e., the coexistence of multiple chronic diseases) increases with age in older adults and is a growing concern worldwide. Multimorbidity has been reported to be a driving factor in the increase of medical expenditures in OECD countries. However, to the best of our knowledge, there is no published research that has examined the associations between multimorbidity and either long-term care (LTC) expenditure or the sum of medical and LTC expenditures worldwide. We, therefore, aimed to examine the associations of multimorbidity with the sum of medical and LTC expenditures for older adults in Japan.

METHODS

Medical insurance claims data for adults ≥75 years were merged with LTC insurance claims data from Kashiwa city, a suburb in the Tokyo metropolitan area, for the period between April 2012 and September 2013 to obtain an estimate of medical and LTC expenditures. We also calculated the 2011 updated and reweighted version of the Charlson Comorbidity Index (CCI) scores. Then, we performed multiple generalized linear regressions to examine the associations of CCI scores (0, 1, 2, 3, 4, or ≥ 5) with the sum of annual medical and LTC expenditures, adjusting for age, sex, and household income level.

RESULTS

The mean sum of annual medical and LTC expenditures was ¥1,086,000 (US$12,340; n = 30,042). Medical and LTC expenditures accounted for 66 and 34% of the sum, respectively. Every increase in one unit of the CCI scores was associated with a ¥257,000 (US$2920); 95% Confidence Interval: ¥242,000, 271,000 (US$2750, 3080) increase in the sum of the expenditures (p < 0.001; n = 29,915).

CONCLUSIONS

Using a merged medical and LTC claims dataset, we found that greater CCI scores were associated with a higher sum of annual medical and LTC expenditures for older adults. To the best of our knowledge, this is the first study to examine the associations of multimorbidity with LTC expenditures or the sum of medical and LTC expenditures worldwide. Our study indicated that the economic burden on society caused by multimorbidity could be better evaluated by the sum of medical and LTC expenditures, rather than medical expenditures alone.

Impact and attribute of each obesity-related cardiovascular risk factor in combination with abdominal obesity on total health expenditures in adult Japanese National Health insurance beneficiaries: The Ibaraki Prefectural health study

Background

The aim of this study was to examine the attribution of each cardiovascular risk factor in combination with abdominal obesity (AO) on Japanese health expenditures.

Methods

The health insurance claims of 43,469 National Health Insurance beneficiaries aged 40–75 years in Ibaraki, Japan, from the second cohort of the Ibaraki Prefectural Health Study were followed-up from 2009 through 2013. Multivariable health expenditure ratios (HERs) of diabetes mellitus (DM), high low-density lipoprotein cholesterol (LDL-C), low high-density lipoprotein cholesterol (HDL-C), and hypertension with and without AO were calculated with reference to no risk factors using a Tweedie regression model.

Results

Without AO, HERs were 1.58 for DM, 1.06 for high LDL-C, 1.27 for low HDL-C, and 1.31 for hypertension (all P < 0.05). With AO, HERs were 1.15 for AO, 1.42 for DM, 1.03 for high LDL-C, 1.11 for low HDL-C, and 1.26 for hypertension (all P < 0.05, except high LDL-C). Without AO, population attributable fractions (PAFs) were 2.8% for DM, 0.8% for high LDL-C, 0.7% for low HDL-C, and 6.5% for hypertension. With AO, PAFs were 1.0% for AO, 2.3% for DM, 0.4% for low HDL-C, and 5.0% for hypertension.

Conclusions

Of the obesity-related cardiovascular risk factors, hypertension, independent of AO, appears to impose the greatest burden on Japanese health expenditures.

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The highest population attributable fraction was for hypertension without obesity.

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The total population attributable fraction of hypertension was 11.7%.

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Hypertension could impose the greatest attribute on Japanese health expenditures.

Relationship between outpatient visit frequency and hypertension control: a 9-year occupational cohort study

The purpose of this study was to investigate the relationship between the frequency of outpatient visits and hypertension control as determined from health insurance records. This 9-year cohort study in Japan was based on 518 participants with hypertension who underwent health checkups in 2004. Participants were aged 35-56 years and none had a history of cardiovascular or cerebrovascular disease. All were covered by the same employee health insurer. Mean annual outpatient visit days at a hospital/clinic during the 9-year period were classified within four quartiles (Q1, Q2, Q3, Q4). Uncontrolled hypertension was defined as a systolic blood pressure (BP) ⩾140 mm Hg and a diastolic BP ⩾90 mm Hg. Logistic regression analysis was used to estimate the multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the prevalence of uncontrolled hypertension in groups Q1, Q2 and Q3 vs. Q4. The median (25th-75th percentile) annual outpatient visit days was 9.4 (4.0-15.5). Uncontrolled hypertension was observed in 62.4% of the participants in 2013. The multivariable-adjusted ORs and 95% CIs for uncontrolled hypertension in Q1, Q2 and Q3 vs. Q4 were 4.03 (2.28-7.12), 1.67 (0.99-2.81) and 1.44 (0.86-2.41), respectively. Uncontrolled hypertension increased significantly as the number of outpatient visits decreased (P for trend <0.001). This tendency was maintained when participants taking antihypertensive agents at baseline were excluded. Our study showed an inverse relationship between outpatient visit frequency and uncontrolled hypertension.

Impact of cardiovascular risk factors on medical expenditure: evidence from epidemiological studies analysing data on health checkups and medical insurance

Concerns have increasingly been raised about the medical economic burden in Japan, of which approximately 20% is attributable to cardiovascular disease, including coronary heart disease and stroke. Because the management of risk factors is essential for the prevention of cardiovascular disease, it is important to understand the relationship between cardiovascular risk factors and medical expenditure in the Japanese population. However, only a few Japanese epidemiological studies analysing data on health checkups and medical insurance have provided evidence on this topic. Patients with cardiovascular risk factors, including obesity, hypertension, and diabetes, may incur medical expenditures through treatment of the risk factors themselves and through procedures for associated diseases that usually require hospitalization and sometimes result in death. Untreated risk factors may cause medical expenditure surges, mainly due to long-term hospitalization, more often than risk factors preventively treated by medication. On an individual patient level, medical expenditures increase with the number of concomitant cardiovascular risk factors. For single risk factors, personal medical expenditure may increase with the severity of that factor. However, on a population level, the medical economic burden attributable to cardiovascular risk factors results largely from a single, particularly prevalent risk factor, especially from mildly-to-moderately abnormal levels of the factor. Therefore, cardiovascular risk factors require management on the basis of both a cost-effective strategy of treating high-risk patients and a population strategy for reducing both the ill health and medical economic burdens that result from cardiovascular disease.

Hypertension and medical expenditure in the Japanese population: Review of prospective studies

Hypertension is a major determinant of health and is likely to have an effect on medical economics. The economic burden due to hypertension may be attributable not only to antihypertensive medication but also to the very expensive procedures required for cases of cardiovascular disease that occur more frequently in hypertensive compared with normotensive individuals. The objective of this article was to review articles published on prospective cohort studies that measured medical expenditure attributable to hypertension in community-dwelling populations in Japan. Many medical services in these populations are provided under the medical insurance system that requires the enrolment of all Japanese residents. Personal medical expenditure attributable to hypertension increases with worsening severity of the condition. Medical expenditure was increased further in cases of hypertensive patients who have another concomitant cardiovascular risk factor. In particular, hypertension, especially moderate-to-severe untreated hypertension, increases the risk of long-term hospitalization resulting in considerably higher medical expenditure, compared with non-hospitalized cases. Therefore, assuming that the use of antihypertensive medication is essential for hypertensive patients to prevent serious vascular diseases, a cost-effective high-risk strategy needs to be considered to reduce both ill-health and the economic burden due to hypertension. However, from a population perspective, medical expenditure attributable to hypertension comes mainly from pre-to-mild hypertension. Therefore, there is also a need to consider a population strategy that aims to shift the entire population to lower levels of blood pressure.

Treated and untreated hypertension, hospitalization, and medical expenditure: an epidemiological study in 314622 beneficiaries of the medical insurance system in Japan

OBJECTIVE

This study investigated the effect of hypertension on hospitalization risk and medical expenditure according to treatment status in a Japanese population.

METHODS

A total of 314 622 beneficiaries of the medical insurance system in Japan, aged 40-69 years, without a history of cardiovascular, cerebrovascular, or end-stage renal disease were classified into seven blood pressure categories. These categories were used to compare the risk of undergoing hospitalization in the 1 year after the baseline survey and to examine the percentage of inpatient medical expenditure attributable to overall hypertension relative to total medical expenditure in the study population.

RESULTS

During the follow-up period, 6.6% of men and 5.1% of women were hospitalized. In men and women aged 40-54 years, cases of hypertension, especially grade 3 untreated hypertension, led to more frequent hospitalization, compared with optimal blood pressure. Individuals who were hospitalized, especially long-term, incurred considerably higher medical expenditure compared with those who were not hospitalized, regardless of their hypertension status. In women aged 55-69 years, there was little variation in hospitalization risk across blood pressure categories. The inpatient medical expenditure attributable to overall hypertension represented 7.2 and 6.9% of the total medical expenditure for men aged 40-54 and 55-69 years, whereas it represented 2.8 and 3.8% for women, respectively.

CONCLUSION

Although cases of hypertension were an economic burden especially in men, grade 3 untreated hypertension was more likely to incur extremely high medical expenditure as a result of hospitalization, compared with other cases.

[Effect of cardiovascular risk factors on individual and population medical expenditures: a 10-year cohort study of 4,535 National Health Insurance beneficiaries in Shiga]

A 10-year follow-up cohort study of 4,535 National Health Insurance beneficiaries aged 40 to 69 years in Shiga was performed as part of a research project conducted by the Health Promotion Research Committee of the Shiga National Health Insurance Organizations in 2002. The relationship between cardiovascular risk factors and medical expenditures during the 10-year study period has been examined in this cohort. For example, there was a positively graded correlation between blood pressure and individual total medical expenditures per month. The odds ratio for cumulative hospitalization and hazard ratio for all-cause mortality in severe hypertensives were also higher than those in normotensives. However, from the viewpoint of the entire population, the excess medical expenditures attributable to hypertension within the total medical expenditures were higher for mild-to-moderate hypertensives than for severe hypertensives. On the other hand, although individual medical expenditures per month were 1.7-fold higher for participants with 2 or 3 risk factors and obesity, which was broadly equivalent to metabolic syndrome, than for those without these factors, the excess medical expenditures determined by risk clustering within the total medical expenditures were higher in normal-weight people than in obese people because of the higher prevalence of normal weight. These findings suggest that high-risk individuals are a good target of a high-risk approach, such as intensive health guidance, from the viewpoint of medical expenditures. However, another approach for the majority with a low-to-moderate cardiovascular risk should be considered, because they account for a greater proportion of the excess medical expenditures. Another way to solve this problem may be a population approach with an effective method of providing information to citizens.

Medical expenditures of men with hypertension and/or a smoking habit: a 10-year follow-up study of National Health Insurance in Shiga, Japan

Hypertension and smoking are major causes of disability and death, especially in the Asia-Pacific region, where there is a high prevalence of a combination of these two risk factors. We attempted to measure the medical expenditures of a Japanese male population with hypertension and/or a smoking habit over a 10-year period of follow-up. A cohort study was conducted that investigated the medical expenditures due to a smoking habit and/or hypertension during the decade of the 1990s using existing data on physical status and medical expenditures. The participants included 1708 community-dwelling Japanese men, aged 40-69 years, who were classified into the following four categories: 'neither smoking habit nor hypertension', 'smoking habit alone', 'hypertension alone' or 'both smoking habit and hypertension.' Hypertension was defined as a systolic blood pressure of > or =140 mm Hg, a diastolic blood pressure of > or =90 mm Hg or taking antihypertensive medications. In the study cohort, 24.9% had both a smoking habit and hypertension. During the 10-year follow-up period, participants with a smoking habit alone (18,444 Japanese yen per month), those with hypertension alone (21,252 yen per month) and those with both a smoking habit and hypertension (31,037 yen per month) had increased personal medical expenditures compared with those without a smoking habit and hypertension (17,418 yen per month). Similar differences were observed even after adjustment for other confounding factors (P<0.01). Japanese men with both a smoking habit and hypertension incurred higher medical expenditures compared with those without a smoking habit, hypertension or their combination.

Age-stratified analysis of the impact of hypertension on National Health Insurance Medical Expenditures in Ibaraki, Japan

Background

This retrospective cohort study examined the sex- and age-specific impact of hypertension on medical expenditures.

Methods

In 2006, we analyzed the medical expenditure records of 42 426 Japanese National Health Insurance beneficiaries (16 169 men, 26 257 women) who lived in Ibaraki, Japan, were aged 40 to 69 years, and underwent health checkups in 2002. Blood pressure was classified into 4 categories according to the criteria outlined in the seventh report of the Joint National Committee.

Results

The difference in median total expenditure between the hypertension categories and the normotension category was 119 585 yen (140 360 yen vs 20 775 yen) for men aged 40 to 54 years, 126 160 yen (204 070 yen vs 77 910 yen) for men aged 55 to 69 years, 125 495 yen (158 025 yen vs 32 530 yen) for women aged 40 to 54 years, and 122 370 yen (208 700 yen vs 86 330 yen) for women aged 55 to 69 years. The median total and outpatient medical expenditures markedly differed between patients with stage 1 hypertension and stage 2 hypertension (which included people on antihypertensive medication) in both sexes and all age subgroups. The median total and outpatient medical expenditures were higher among women than among men in all blood pressure categories.

Conclusions

The impact of hypertension on medical expenditures was similar in all age groups. Therefore, from the perspective of medical economics, prevention of the onset of hypertension seems equally important for all age subgroups.

Asymptomatically elevated blood pressure in the emergency department: a finding deserving of attention by emergency physicians?

The Emergency Department (ED) may be an ideal place to screen and refer patients for blood pressure monitoring in the outpatient setting. Yet, little is known about the public health significance of asymptomatically elevated blood pressure measurements in the ED and what to tell patients when these abnormal vital signs are recorded. Since the prevalence of hypertension and inadequately treated hypertension is so high, the incidental finding of elevated blood pressure in a previously undiagnosed patient may be a pivotal moment in that patient's life. For those patients carrying the diagnosis of hypertension, it is the author's opinion that the observation of elevated blood pressures should trigger advice to see their physicians to consider medication adjustments or changes. Emergency Physicians and their staff are in a unique position to screen and refer large populations of patients to their community physicians and help abort the long-term sequelae of unidentified or inadequately managed hypertension. How best to advise physicians and their patients requires research and innovative methods for transmitting important information to patients that may be unrelated to their primary complaint in the ED.

Effect of chronic kidney disease on individual and population medical expenditures in the Japanese population

Chronic kidney disease (CKD) is associated with increased risk of cardiovascular disease (CVD), and may also lead to an increase in medical expenditures. The effect of CKD on individual and population medical expenditures was examined in a Japanese cohort study. The participants included 4026 Japanese National Health Insurance beneficiaries aged 40-74 years living in one city, who had no history of major CVD. They were classified into three categories according to their glomerular filtration rate (GFR) at the baseline survey, and their total medical expenditures were followed-up for 3 years. The arithmetic and geometric means of the cumulative medical expenditures were calculated for each category. The geometric mean was also expressed after adjusting for several confounding factors using analysis of covariance. The CKD-related medical expenditures attributable to the participants with mild (60 < or = GFR < 90) or moderate (30 < or = GFR < 60) kidney dysfunction were compared with those of participants with normal (GFR > or = 90) kidney function. There was a negative correlation between the GFR category and the arithmetic and geometric means of personal medical expenditures (adjusted geometric mean: GFR > or = 90, 167,879 yen; 60 < or = GFR < 90, 210,660 yen; and 30 < or = GFR < 60, 330,050 yen). The CKD-related medical expenditures accounted for 11.5 and 6.5% of the total medical expenditures for the participants with mild and moderate kidney dysfunction, respectively. The prevention of mild CKD is very important for containing medical expenditures. Appropriate strategies, such as regular creatinine measurement, are needed for early detection of CKD.

The joint impact of cardiovascular risk factors upon medical costs

OBJECTIVE

The joint impact of obesity, hypertension, and hyperglycemia upon medical costs is not well known. Our objective was to evaluate the joint impact of these cardiovascular risk factors upon medical costs in the rural Japanese population.

METHODS

The data were derived from a 6-year prospective observation of National Health Insurance beneficiaries in rural Japan. Data on blood chemistry tests, blood pressure, weight, and height were obtained from an annual health check-up provided by the local municipalities in 1995. We prospectively collected data on medical costs over a 6-year period for 12,340 subjects (5306 men and 7034 women) without prior histories of cardiovascular disease or cancer.

RESULTS

Mean medical costs for individuals being overweight/obese, hypertensive, and hyperglycemic were 91.0% higher than those for individuals without any of these three cardiovascular risk factors. In this cohort, 17.2% of total medical costs were attributable to these three risk factors.

CONCLUSION

Overweight/obesity, hypertension, and hyperglycemia could have a large impact on health care resources in rural Japan.

Medical costs of obese Japanese: a 10-year follow-up study of National Health Insurance in Shiga, Japan

BACKGROUND

For the Japanese population, a body mass index (BMI) of 25.0-29.9 is classified as obesity and is a risk factor for cardiovascular disorders such as hypertension.

METHODS

A cohort study to clarify obesity costs for a Japanese population was conducted utilizing baseline BMI and medical costs over a 10-year follow-up period. The participants were 4502 community dwelling Japanese National Health Insurance (NHI) beneficiaries aged 40-69 years. According to their baseline BMI values (kg/m(2)), participants were classified into the following three categories: BMI < 18.5, 18.5 < or = BMI < 25.0 and 25.0 < or = BMI. Medical costs per person per month were compared among the three categories. Excess medical costs attributable to the 25.0 < or = BMI category compared to the 18.5 < or = BMI < 25.0 category were estimated.

RESULTS

Approximately 20% of the Japanese population studied had a BMI of 25.0 or over. A J-shaped relationship between BMI and personal total medical costs was observed. Personal total medical costs per month determined from the 10-year follow-up in each category were 189 Euros (BMI < 18.5), 134 Euros (18.5 < or = BMI < 25.0) and 155 Euros (25.0 < or = BMI). A J-shaped pattern was observed after adjusting for age, sex, smoking and drinking habits, and excluding early deceased participants. Furthermore, smoking habit did not modify the J-shaped pattern of total medical costs. The estimated excess medical costs for the 25.0 < or = BMI category represented 3.1% of the total medical costs for the entire study population (634 105 Euros).

CONCLUSION

The Japanese NHI beneficiaries with a BMI of 25.0 or over showed increased medical costs compared to those with a BMI of 18.5-24.9.

Effect of Combined Cardiovascular Risk Factors on Individual and Population Medical Expenditures

BACKGROUND

Although obesity is required for some criteria defining metabolic syndrome, clustering of other risk factors also indicates an increased risk of cardiovascular disease. Whether the relationship between cardiovascular risk factor clustering and medical expenditures differs with body mass index (BMI) requires investigation, especially in a population with a low prevalence of obesity such as that in Japan.

METHODS AND RESULTS

A 10-year cohort study of 4,478 Japanese National Health Insurance beneficiaries aged 40-69 years in a community between 1990 and 2001 was carried out in the present study. The clustering of cardiovascular risk factors showed a positive and graded relationship to personal medical expenditures in participants who are overweight (BMI > or =25.0) and normal weight (BMI <25.0). The individual medical expenditures per month were 1.7-fold higher for participants with 2 or 3 risk factors and overweight than for those without these factors (26,782 vs 15,377 Japanese yen). Differences in the geometric means were similarly significant after adjustment for other confounding factors. However, the excess medical expenditures by risk clustering of normal weight categories within the total medical expenditures were higher than those of overweight categories because more participants were of normal weight.

CONCLUSIONS

Cardiovascular risk factor clustering and being overweight can be a useful predictor of medical expenditures in a Japanese population.

Medical costs of patients with hypertension and/or diabetes: A 10-year follow-up study of National Health Insurance in Shiga, Japan

BACKGROUND AND METHODS

A cohort study investigating medical costs associated with the combination of hypertension and diabetes was conducted. The participants included 4535 community-dwelling Japanese individuals, aged 40-69 years, who were classified into the following four categories: 'Neither hypertension nor diabetes', 'Hypertension alone', 'Diabetes alone' or 'Both hypertension and diabetes'. Medical costs per person per month were compared among the four categories.

RESULTS AND CONCLUSION

Of the study population, 1.3% had both hypertension and diabetes. During the 10-year follow-up period, participants with both hypertension and diabetes incurred higher medical costs, as compared with those without hypertension, diabetes or their combination, even after adjustment for other confounding factors.