Impact of Income Disparity on Utilization of Home-Based Care Services Among Older Adults in Japan: A Retrospective Cohort Study.

This study aimed to determine whether there are disparities in the utilization of home-based care services according to income level among people aged 75 years or older in Japan. The research team used administrative claims data from April 2014 to March 2018 for people aged 75 years or older in Fukuoka Prefecture. Subjects were categorized according to income level using medical insurance claim data. Associations between income level and usage days of inpatient care, outpatient care, home medical care, and usage number of home-based long-term care (LTC) services were evaluated. Furthermore, medical and LTC costs were evaluated and adjusted for gender, age, and level of LTC needs. The team used generalized linear models (GLMs) to estimate medical and LTC services utilization, as well as the potential influence of gender, age, care needs level, and death as risk factors. The study analyzed 31,322 subjects, among whom 17,288 were in low-, 12,755 were in middle-, and 1399 were in high-income groups. The results of GLMs showed the number of home medical care days was 59.45, 62.24, and 69.66 days for users from low-, middle-, and high-income groups, respectively. Correspondingly, the number of home-based LTC services used was 668.84, 709.59, and 833.14 times. This study suggests that older adults with lower incomes had relatively low utilizations of home-based care services and high utilizations of nonhome-based LTC services. Policymakers should implement policies focused on people who need care to tackle socioeconomic inequalities in home-based care.

Cost-Sharing Effects on Hospital Service Utilization Among Older People in Fukuoka Prefecture, Japan.

BACKGROUND: The cost-sharing impact on hospital service utilization of different services is a critical issue that has not been well addressed worldwide. This study aimed to investigate the cost-sharing effects based on income status on hospital service utilization of different services among elderly people in Japan and provide a comprehensive examination and discussion for the reasonability of a cost-sharing system. METHODS: The data were extracted from the Latter-Stage Elderly Healthcare Insurance database in the fiscal year 2016. A total of 610 182 insured people aged ≥75 years old, with 155 773 hospitalization patients, were identified. Hospitalization rate, length of stay (LOS), and total hospitalization cost were used to test the statistical significance among patients categorized by income levels. Generalized linear models for total hospitalization cost were constructed based on bed types to further assess different hospital service utilization. RESULTS: For medical chronic care and psychiatric beds, which both required long-term care treatment, much higher hospitalization rates were observed in the patients with low- and middle-income levels than patients with high-income level. The LOS and total hospitalization cost of the patients with low- and middle-income levels were significantly higher than the patients with high-income level treated in medical chronic care and psychiatric beds. For psychiatric beds, the total hospitalization cost for patients with low-income level was significantly higher than that for patients with highincome level. CONCLUSION: The cost-sharing policy in Japan, especially the cap for out-of-pocket needs further determination. The importance of community-based care services needs to be emphasized, and the collaboration between hospitals and community-based care facilities should be enhanced.

Cost-effectiveness analysis of treatment with varenicline for nicotine dependence compared with smoking cessation without pharmacotherapy in the real world.

PURPOSE: Smoking is an important public health issue. Although measures to support smoking cessation have been implemented worldwide, smokers often fail to quit smoking after receiving pharmacotherapies for nicotine dependence. The present study evaluated the cost-effectiveness of varenicline for smoking cessation compared with no pharmacotherapy using actual paid medical cost data in Japan. METHODS: This was a retrospective cohort study of 3657 subjects who had quit smoking with varenicline or no pharmacotherapy. We extracted health examination and medical claim data from a health insurer database for the period 2012-2015. We calculated the incremental cost-effective ratio (ICER) of varenicline using actual paid medical costs for nicotine dependence and the number needed to treat to maintain smoking cessation compared with no pharmacotherapy, considering sex, age, income, and occupation. RESULTS: The 1- and 2-year smoking cessation maintenance rates were 69.7% and 62.4%, respectively. We found that 8.8% of subjects who quit smoking used varenicline for nicotine dependence and the cost per person was Japanese Yen (JPY) 52 177 (U.S. dollars [USD] 474; USD 1 = JPY 110). The ICER of varenicline was dominant when comparing 2-year cessation with 1-year cessation. Male, age <40 years, low income, and manufacturing workers were the most cost-effective variables. CONCLUSIONS: The cost-effective variables of varenicline in the real world were investigated. The results of this study strengthen the evidence regarding which type of people should be targeted for measures to support smoking cessation using varenicline.

Health Inequality Among Older Adults with Percutaneous Coronary Intervention and Universal Health Coverage in Japan.

This study aimed to comprehensively evaluate whether income affects long-term health outcomes for older patients who underwent percutaneous coronary intervention (PCI) provided by a universal health coverage system. Data were from the Latter Stage Elderly Healthcare Insurance database in Fukuoka Prefecture, Japan. A total of 5625 individuals aged ≥65 years who underwent PCI in 2014-2016 were included. Cox proportional hazards models were used to assess the association between income status and the incidence of health outcomes. With a median follow-up of 1095 days, 554 acute myocardial infarction (AMI) cases, 1075 stroke cases, 1690 repeat revascularization cases, and 1094 deaths were observed. Risk of all-cause mortality decreased significantly with increasing income level in both unadjusted and adjusted Cox regression models. Patients in the low-income level had a significantly higher rate of AMI (log-rank P = 0.003), stroke (log-rank P = 0.039), and all-cause mortality (log-rank P = 0.001) compared with patients in the high-income level. Observed rates for repeat revascularization also were high in the first year after PCI. In the Japanese universal health setting, low-income patients had a comparatively higher mortality risk after PCI. Poor long-term outcomes might be attributed to patients' baseline characteristics rather than treatment processes.

Effects of physician visit frequency for Parkinson's disease treatment on mortality, hospitalization, and costs: a retrospective cohort study.

BACKGROUND: The number of patients with Parkinson's disease among older adults is rapidly increasing. Such patients mostly take medication and require regular physician visits. However, the effect of physician visit frequency for the treatment for Parkinson's disease has not been evaluated. This study aimed to evaluate the impact of physician visit frequency for Parkinson's disease treatment on mortality, healthcare days, and healthcare and long-term care costs among older adults. METHODS: This study employed a retrospective cohort design utilizing claims data from the Fukuoka Prefecture Wide-Area Association of Latter-Stage Elderly Healthcare Insurance and Long-Term Care Insurance. Patients aged ≥75 years who were newly diagnosed with Parkinson's disease in 2014 were included in this study, following the onset of Parkinson's disease to March 31, 2019. We calculated the restricted mean survival time to evaluate mortality, focusing on the frequency of physician visits for Parkinson's disease treatment. Inpatient days, outpatient days, and healthcare and long-term care costs per month were calculated using a generalized linear model. RESULTS: There were 2224 participants, with 46.5% mortality among those with a higher frequency of physician visits and 56.4% among those with a lower frequency of physician visits. A higher frequency of physician visits was associated with a significant increase in survival time (1.57 months at 24 months and 5.00 months at 60 months) after the onset of Parkinson's disease and a decrease in inpatient days and healthcare costs compared to a lower frequency of physician visits. CONCLUSIONS: A higher frequency of physician visits was significantly associated with longer survival time, fewer inpatient days, and lower healthcare costs. Caregivers should support patients with Parkinson's disease to visit physicians regularly for their treatment.

Impact of the 2014 coinsurance rate revision for the elderly on healthcare resource utilization in Japan.

BACKGROUND: Cost sharing, including copayment and coinsurance, is often used to contain medical expenditure by decreasing unnecessary or excessive use of healthcare resources. Previous studies in Japan have reported the effects of a coinsurance rate reduction for healthcare from 30 to 10% on the demand for healthcare among 70-74-year-old individuals. However, the coinsurance rate for this age group has recently increased from 10 to 20%. This study aimed to estimate the economic impact of coinsurance rate revision on healthcare resource utilization. METHODS: We collected claims data from beneficiaries of the municipality National Health Insurance and the Japanese Health Insurance Association in Fukuoka Prefecture. We categorized subjects born between March 2, 1944 and April 1, 1944 into the 20% coinsurance rate reduction group and those born between April 2, 1944 and May 1, 1944 into the 10% reduction group. An interrupted time-series analysis for multiple groups was employed to compare healthcare resource utilization trends before and after coinsurance rate reduction at 70 years. RESULTS: The 10% coinsurance rate reduction led to a significant increase in healthcare expenditure for outpatient care. The 20% reduction group showed a significantly sharper increase in healthcare expenditure for outpatient care than the 10% reduction group. Similarly, the 10% coinsurance group significantly increased in the number of ambulatory visits. The 20% coinsurance rate reduction group had more frequent ambulatory care visits than the 10% reduction group. CONCLUSIONS: These results suggest that increasing the coinsurance rate among the elderly would reduce outpatient healthcare resource utilization; however, it would not necessarily reduce overall healthcare resource utilization.

Effect of Care Rehabilitation on Medical Expenses, Care Costs, and Total Costs of Elderly Individuals with Parkinson's Disease.

The fast-growing prevalence of Parkinson's disease (PD) creates a heavy burden for society and the health care system. Although different ways to mitigate the economic burden of PD have been discussed in the literature, including several effective treatments, few studies have paid attention to the effect of care rehabilitation (CR) on PD costs over a long-term care period. This study tracked medical expenses, care costs, and total costs of elderly individuals with PD for 3 years based on medical claims data merged with long-term care insurance (LTCI) claims data, and determined whether CR reduced PD costs. Using a retrospective, longitudinal cohort design, 3950 elderly individuals with PD who received LTCI services from April 2014 to March 2017 in Fukuoka Prefecture, Japan were followed. PD costs were compared between the CR group and the non-CR group, and a hierarchical linear model was used to examine whether CR was associated with medical expenses, care costs, and total costs. The mean value of total costs in fiscal years 2014, 2015, and 2016 were ¥3,124,944 (US$29,504), ¥3,328,398 (US$31,425), and ¥3,615,892 (US$34,140), respectively. In a hierarchical linear model, CR alone was not associated with medical expenses and care costs; additionally, CR had a positive association with higher total costs. However, the interaction term between CR and baseline care needs level significantly reduced care costs and total costs. That indicates that if older PD patients with higher care needs level receive CR, their care costs and total costs will be reduced. Further research is needed to clarify how CR reduces these patients' costs.

Multilevel analysis of hemodialysis-associated infection among end-stage renal disease patients: results of a retrospective cohort study utilizing the insurance claim data of Fukuoka Prefecture, Japan.

The presence of comorbid conditions along with heterogeneity in terms of healthcare practices and service delivery could have a significant impact on the patient's outcomes. With a strong interest in social epidemiology to examine the impact of health services and variations on health outcomes, the current study was conducted to analyse the incidence of hemodialysis-associated infection (HAI) as well as its associated factors, and to quantify the extent to which the contextual effects of the care facility and regional variations influence the risk of HAI.A total of 6111 patients with end-stage renal disease who received hemodialysis treatment between 1 October 2015 and 31 March 2016 were identified from the insurance claim database as a population-based, close-cohort retrospective study. Patients were followed for one year from April 1, 2016 to March 31, 2017. A total of 200 HAI cases were observed during the follow-up and 12 patients died within 90 days of the onset of HAI. Increased risks for HAI were associated with moderate (HR 1.73, 95% confidence interval [CI] 1.00-2.98) and severe (HR 1.87, 95% CI 1.11-3.14) comorbid conditions as well as malignancy (HR 1.36, 95% CI 1.00-1.85). Increased risk was also seen among patients who received hemodialysis treatment from clinics (HR 2.49, 95% CI 1.1-5.33). However, these statistics were no longer significant when variations at the level of care facilities were statistically controlled. In univariate analyses, no statistically significant association was observed between 90-day mortality and baseline patients, and the characteristics of the care facility.The results of the multivariate, multilevel analyses indicated that HAI variations were only significant at the care facility level (σ 2.07, 95% CI 1.3-3.2) and were largely explained by the heterogeneity between care facilities. The results of this study highlight the need to look beyond the influence of patient-level characteristics when developing policies that aim at improving the quality of hemodialysis healthcare and service delivery in Japan.

Influence of Occupational Background on Smoking Prevalence as a Health Inequality Among Employees of Medium- and Small-Sized Companies in Japan.

Tobacco smoking is a major public health problem. In addition, the influence of socioeconomic status on health inequalities has received great attention worldwide. The authors used insurance data of beneficiaries employed in medium- and small-sized Japanese companies to investigate the influence of occupational background on smoking prevalence as a health inequality among workers in Japan. Participants were aged 35-74 years and underwent health examinations in 2015. Smoking prevalence was estimated for each occupational group according to sex, age, and income. Logistic regression analysis was used to assess the association between smoking status and occupational groups. A total of 385,945 participants were included. Overall smoking prevalence was 36.3%, higher than average in Japan. Smoking prevalence was lowest among workers in the education and learning support category; all other occupational groups had significantly high prevalence, with the highest for transport and postal services (odds ratio 2.69, 95% confidence interval 2.53-2.86). There were few differences in smoking prevalence at higher income levels among female participants, but differences were remarkably significant at lower income levels. For health inequalities related to smoking, occupational background was associated with smoking prevalence. In particular, there was high smoking prevalence in workplaces not covered by smoke-free policies. These results also demonstrated differences between the sexes; smoking prevalence among female workers with lower income levels was strongly associated with occupational background whereas there were no large differences among male workers by income. These findings suggest that the government should encourage companies to adopt smoke-free policies in the workplace.

Health Inequalities Among Elderly Type 2 Diabetes Mellitus Patients in Japan.

The influence of socioeconomic status (SES) on health inequalities has received much attention worldwide. This study examined the effect of SES on the following older type 2 diabetes mellitus patient health outcomes: oral hypoglycemic agent (OHA) medication adherence (proportion of days covered, PDC), risk of hospitalization for diabetic macrovascular complications, and in-hospital death. A retrospective cohort design using 2013-2016 claims data was used. Subjects were 58,349 diabetes patients aged >74 years in 2013. Age, sex, residential area, and comorbidities were controlled for. Logistic regression was conducted to assess the effects of income on PDC; survival analysis was used to assess the effects on hospitalization and in-hospital death. Regressions were conducted separately by sex. Compared with the lowest income group, adjusted PDC odds ratios for medium- and high-income males, respectively, were 1.35 (95% CI: 1.27-1.43) and 1.41 (95% CI: 1.30-1.54); females: 1.17 (95% CI: 1.11-1.23) and 1.24 (95% CI: 1.13-1.35). Adjusted hazard ratios (AHRs) for male hospitalization were 0.88 (95% CI: 0.80-0.96) and 0.88 (95% CI: 0.79-0.99); females: 1.00 (95% CI: 0.93-1.07) and 0.95 (95% CI: 0.83-1.08). AHRs for male in-hospital death were 0.83 (95% CI: 0.75-0.91) and 0.62 (95% CI: 0.54-0.70); females: 0.94 (95% CI: 0.87-1.02) and 0.77 (95% CI: 0.65-0.92). Results revealed sex-specific health inequalities among older Japanese diabetes patients. Subjects with worse SES had significantly poorer OHA medication adherence (both sexes), higher hospitalization risk for diabetes complications (males), and higher in-hospital death risk (both sexes).

Association between income levels and irregular physician visits after a health checkup, and its consequent effect on glycemic control among employees: A retrospective propensity score-matched cohort study.

AIMS/INTRODUCTION: The present study aimed to evaluate the effects of income levels on physician visit patterns and to quantify the consequent impact of irregular physician visits on glycemic control among employees' health insurance beneficiaries in Japan. MATERIALS AND METHODS: We obtained specific health checkup data of untreated diabetes patients from the Fukuoka branch of the Japanese Health Insurance Association. We selected 2,981 insurance beneficiaries and classified 650 and 2,331 patients into, respectively, the regular visit and irregular visit group. We implemented propensity score matching to select an adequate control group. RESULTS: Compared with those with a standard monthly income <$2,000 (US$1 = ¥100), those with a higher monthly income were less likely to have irregular visits; $2,000-2,999: odds ratio 0.74 (95% confidence interval 0.56-0.98), $3,000-3,999: odds ratio 0.63 (95% confidence interval 0.46-0.87) and ≥$5,000: odds ratio 0.58 (95% confidence interval 0.39-0.86). After propensity score matching and adjusting for covariates, the irregular visit group tended to have poor glycemic control; increased glycated hemoglobin ≥0.5: odds ratio 1.90 (95% confidence interval 1.30-2.77), ≥1.0: odds ratio 2.75 (95% confidence interval 1.56-4.82) and ≥20% relatively: odds ratio 3.18 (95% confidence interval 1.46-6.92). CONCLUSIONS: We clarified that there was a significant relationship between income and irregular visits, and this consequently resulted in poor glycemic control. These findings would be useful for more effective disease management.

Effects of gastrostomy fee schedule revision on artificial nutrition routes among older people with dementia in Japan: A time series observational study.

AIM: The present study aimed to investigate the effects of the 2014 Japanese fee schedule revision on trends in artificial nutrition routes, including gastrostomy, nasogastric tube and parenteral nutrition, among older people with dementia, using time series analysis. METHODS: The study used claim data in Japan submitted to Fukuoka Late Elders' Health Insurance from fiscal year 2010 to fiscal year 2016. We identified older people with dementia provided for the first time with artificial nutrition via gastrostomy, nasogastric tube or central venous line and aggregated their data by month. Interrupted time series analyses were used to examine trends in artificial nutrition routes over time. RESULTS: The numbers of older people with dementia receiving nutrition via gastrostomy, nasogastric tube and parenterally declined consistently. The slopes for pre-revision trends in gastrostomy, nasogastric tube and parenteral nutrition procedures were all significantly negative in the interrupted time series analyses. The post-revision trends in gastrostomy and parenteral nutrition continuously had significant negative slopes. In contrast, the significant negative trend in nasogastric tube procedures in the pre-revision period had disappeared during the post-revision period. CONCLUSIONS: The study showed that the fee schedule revision had limited impact on gastrostomy and parenteral nutrition. However the trend for nasogastric tube was ambiguous; hence, sustainable surveillance is required for evidence-based health policy. Geriatr Gerontol Int 2018; 18: 1405-1409.

Association Between Financial Incentives for Regional Care Coordination and Health Care Resource Utilization Among Older Patients after Femoral Neck Fracture Surgery: A Retrospective Cohort Study Using a Claims Database.

The incidence rates of hip fracture have been increasing in Japan. Length of stay among hip fracture patients in Japan is much longer than other developed countries, and the Japanese government introduced financial incentives for regionally coordinated femoral neck fracture care to reduce health care resource utilization. The objective of this study was to evaluate whether the financial incentives reduce health care resource utilization among patients 75 years or older with femoral neck fracture in Japan. Claims data from the Fukuoka Prefecture Regional Association for Late-Stage Healthcare for Older People were analyzed for the period from April 2010 to March 2016. The authors identified 4641 eligible subjects after femoral neck fracture surgery, and categorized them into groups based on care pathways: coordinated care, integrated care, and other. Length of stay by care phase and total charges were used as measures of health care resource utilization. The models showed that coordinated and integrated care were significantly associated with shorter length of stay during perioperative care: coordinated care, multiplicative effect, 0.90 (P < 0.001); integrated care, 0.77 (P < 0.001). However, only integrated care was associated with shorter rehabilitation and overall length of stay: 0.66 (P < 0.001) in rehabilitation; 0.70 (P < 0.001) in overall duration. Integrated care also was associated with lower total charges: 0.70 (P < 0.001). Current financial incentives for regionally coordinated femoral neck fracture care do not affect health care resource utilization. Further health care reforms should be implemented to promote effective regional care coordination in Japan.

Impact of financial incentives for inter-provider care coordination on health-care resource utilization among elderly acute stroke patients.

OBJECTIVE: To examine the impact of inter-provider care coordination on health-care resource utilization among elderly acute stroke patients. DESIGN: A retrospective cohort study using health-care insurance claims data. SETTING: Claims data of the Fukuoka Prefecture Wide-Area Association of Latter-Stage Elderly Healthcare. PARTICIPANTS: About, 6409 patients aged 75 years or older admitted for acute stroke and moved to rehabilitation wards from 1 April 2010 to 30 September 2015. MAIN OUTCOME MEASURE: Lengths of stay (LOS) and total charge (TC) were evaluated according to three groups of care pathways (coordinated care, integrated care and other pathways). RESULTS: Compared with the other care pathway, the coordinated care groups had significantly shorter LOS of 2.0 days in acute ischemic stroke care; they had 2.5 days shorter LOS in hemorrhagic stroke care. However, there were no significant differences in rehabilitation care LOS and TC. CONCLUSIONS: Our findings suggest that a payment system for care coordination is inappropriate since it was not associated with a reduction in overall health-care resource utilization. Further, health-care system reform is necessary to improve care continuity across multiple health-care institutions in Japan.

Investigation into the causes of indwelling urethral catheter implementation and its effects on clinical outcomes and health care resources among dementia patients with pneumonia: A retrospective cohort study.

There is a possibility that unnecessary treatments and low-quality medical care, such as inappropriate indwelling urethral catheter use, are being provided to older Japanese individuals.The aim of this study was to investigate contextual effects relating to indwelling urethral catheters in older people with dementia and to clarify the effects of indwelling urethral catheter use on patients' mortality, length of stay (LOS), and health care spending. This retrospective cohort study involved 4501 male and female Japanese participants. Those who were aged 75 or older with dementia and had a primary diagnosis of acute lower respiratory disease with antibiotics administered during hospitalization were eligible for inclusion. Patient mortality, LOS, and total charge during hospitalization were the main study outcomes. This study showed that indwelling urethral catheter use was significantly associated with higher mortality, longer LOS, and higher total charge for hospitalization. The pattern of indwelling urethral catheter use was clustered by care facility level. Physician density was significantly associated with indwelling urethral catheter use; the relationship was not linear but U-shaped, such that the approximate median had the lowest rate of urethral catheter use and this increased gradually toward both lower and higher physician densities. Our study found considerable variation in indwelling urethral catheter use between care facilities in older people with dementia. Additionally, indwelling urethral catheter use was related to poor outcomes. Based on these findings, we consider there to be an urgent need for constructing a framework to measure, report on, and promote the improvement of care quality for older individuals in Japan.

Investigation of the Existence of Supplier-Induced Demand in use of Gastrostomy Among Older Adults: A Retrospective Cohort Study.

The aim of this study is to clarify whether there is small area variation in the use of gastrostomy that is explained by hospital physician density, so as to detect the existence of supplier-induced demand (SID).The study design is a retrospective cohort using claim data of Fukuoka Late Elders' Health Insurance, submitted from 2010 to 2013. Study participants included 51,785 older adults who had been diagnosed with eating difficulties. We designated use of gastrostomy as an event. Multilevel logistic analyses were then used to investigate the existence of SID.After controlling for patient factors, we found significant regional level variance in gastrectomy use (median odds ratio [MOR]: 1.72, 1.37-2.51). Hospital physician density was significantly positively related with gastrostomy (adjusted OR of hospital physician density: 1.75, 1.25-2.45; P < 0.001). MORs were largely reduced for the input variable of hospital physician density.We found that the small area variation in use of gastrostomy among older adults could be explained by hospital physician density, which might indicate the existence of SID.

Influence of psychiatric disorders on surgical outcomes and care resource use in Japan.

OBJECTIVE: The aim of this study was to quantify the effects of psychiatric disorders on major surgery outcomes and care resource use. METHODS: This study adopted a retrospective cohort study design. The samples consisted of hospital stays. Subjects were patients who had undergone major surgery. We used multilevel regression analysis to quantify the influence of psychiatric disorders on major surgery outcomes and care resource use. RESULTS: The total number of hospital stays included in the study was 5569, of which 250 were patients with psychiatric disorders. Compared with those without psychiatric disorders, those with schizophrenia had a significantly higher risk of complications, and those with neurotic disorder tended to have fewer complications. Total cost was significantly higher for those with schizophrenia and mood disorder and significantly lower in those with neurotic disorder. Lengths of stay were significantly longer for those with schizophrenia and mood disorder but not for those with neurotic disorder. Post-surgical mortality was equivalent among those with any psychiatric disorder and among those without a psychiatric disorder. CONCLUSION: The study revealed that surgical outcomes and care resource use are differentiated by psychiatric disorders.

Could investment in preventive health care services reduce health care costs among those insured with health insurance societies in Japan?

This study examined the impact of expenditures for preventive health care services on health care costs among those insured with health insurance societies in Japan using cross-sectional and longitudinal designs. The subjects of the study were those insured with Japan's 1481 health insurance societies belonging to the National Federation of Health Insurance Societies in 2003 and 2007. Multiple regression analyses were conducted using the forced entry method. Case rates, number of service days, and health care costs were used as dependent variables, and preventive health care expenditures, average age, number of the insured, gender ratio, average monthly salary, and dependents ratio were used as independent variables. Expenditures for preventive health care services showed significant negative correlations with both the number of service days and health care costs for inpatient and outpatient services in 2003 and 2007. The results showed that expenditures for preventive health care services had a negative relationship with health care costs. Thus, these findings support the effects of investment in preventive health activities as promoted by health insurance societies to reduce health care costs.

Does co-payment rate influence the relationship between monthly salary and health care service demand among the insured of health insurance societies in Japan?

The co-payment rate for health care services for insured people increased from 10% to 20% in 1997, and then to 30% in 2003 under the Employed Health Insurance System in Japan. The purpose of this study is to quantify the relationship between average monthly salary and health care service demand by different co-payment rates among the insured of health insurance societies in Japan. Data from the National Federation of Health Insurance Societies from 1996, 2002, and 2007 were analyzed. Indicators of health care service demand included case rates and number of service days per case for inpatient, outpatient, and dental services. The authors evaluated the relationship of average monthly salary with these indicators using multiple regression analyses for each of the 3 years. In the study, the average monthly salary showed a high positive correlation with outpatient and dental case rates for all 3 years. The magnitude of the relationship of average monthly salary to health care service demand was intensified as patient co-payment increased from 10% to 20%. However, it did not change when the co-payment increased from 20% to 30%. The increase in patient co-payment rate from 20% to 30% did not intensify the relationship between average monthly salary and health care service demand among the insured of health insurance societies in Japan.

Assessing the impact of diabetes-related comorbidities and care on the hospitalization costs for patients with diabetes mellitus in Japan.

OBJECTIVE: Because diabetes mellitus (DM) has been highlighted in several healthcare sectors, variations in the case mix of DM should be evaluated to promote effective disease management. Using a Japanese administrative database (2003), we investigated the impact of DM-related comorbidities and of their relevant care processes on healthcare costs incurred during hospitalization. METHODS: Of 283,771 hospital admissions across 174 acute care hospitals, 27,853 patients with DM were analyzed. The following variables were analyzed according to age (<65 or ≥65 years), the presence of comorbidities, demographic characteristics, procedure-related complications, insulin use, surgical procedures (percutaneous minimally invasive intervention, hemodialysis, ventilation, and rehabilitation), length of stay (LOS), and total charge (TC; US$1=Y90). Multivariate analyses were applied to investigate the effects of DM-related complications and care processes associated with DM on TC. RESULTS: The mortality and procedure-related complication rates were 2.1% and 2.7%, respectively. There were significant differences in the frequencies of comorbidities by age category. Among DM-related comorbidities, peripheral vascular disease had the greatest impact on increasing the LOS or TC. Minimally invasive procedures, hemodialysis, ventilation, and procedure-related complications were significant determinants of TC. Hemodialysis and invasive surgical procedures were independent predictors of procedure-related complications. CONCLUSIONS: DM-related comorbidities and care process representative of the DM case mix were responsible for variations in healthcare costs during hospitalization.