Medical expenditure for diabetic patients: a 10-year follow-up study of National Health Insurance in Shiga, Japan

Impact of obesity on annual medical expenditures and diabetes care in Japanese patients with type 2 diabetes mellitus

AIMS/INTRODUCTION

Diabetes and obesity are important health and economic concerns. We investigated the influence of obesity on diabetes control, the annual medical expenditures and medications in Japanese patients with type 2 diabetes who were relatively lean in comparison with those in Western countries.

MATERIALS AND METHODS

A total of 402 Japanese patients with type 2 diabetes were enrolled and their annual medical expenditures investigated. Obesity was defined as body mass index ≥25 kg/m2 , according to the obesity classifications from the Japan Society for the Study of Obesity.

RESULTS

A total of 165 patients (41.0%) were classified as obese. The obese group was younger, had poor glycemic control and higher frequency of hypertension than the non-obese group. The median total annual medical expenditures for all participants was ¥269,333 (interquartile range ¥169,664-437,437), which was equivalent to approximately $US2,450. The annual medical expenditure was significantly higher in patients with obesity than in non-obese patients (P < 0.001). This difference was mainly attributed to the annual expenditures for medication and hospitalization. In particular, the medication expenditures and the average number of drug classes for hyperglycemia and hypertension were significantly higher in the obese group.

CONCLUSIONS

Japanese patients with type 2 diabetes and obesity had higher annual medical expenditures and a larger number of medications, but their diabetes control care was insufficient in comparison with those without obesity. Further studies are required to assess the effect of reducing bodyweight on diabetes control and costs.

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.

The Economic Costs of Type 2 Diabetes: A Global Systematic Review

BACKGROUND

There has been a widely documented and recognized increase in diabetes prevalence, not only in high-income countries (HICs) but also in low- and middle-income countries (LMICs), over recent decades. The economic burden associated with diabetes, especially in LMICs, is less clear.

OBJECTIVE

We provide a systematic review of the global evidence on the costs of type 2 diabetes. Our review seeks to update and considerably expand the previous major review of the costs of diabetes by capturing the evidence on overall, direct and indirect costs of type 2 diabetes worldwide that has been published since 2001. In addition, we include a body of economic evidence that has hitherto been distinct from the cost-of-illness (COI) work, i.e. studies on the labour market impact of diabetes.

METHODS

We searched PubMed, EMBASE, EconLit and IBSS (without language restrictions) for studies assessing the economic burden of type 2 diabetes published from January 2001 to October 2014. Costs reported in the included studies were converted to international dollars ($) adjusted for 2011 values. Alongside the narrative synthesis and methodological review of the studies, we conduct an exploratory linear regression analysis, examining the factors behind the considerable heterogeneity in existing cost estimates between and within countries.

RESULTS

We identified 86 COI and 23 labour market studies. COI studies varied considerably both in methods and in cost estimates, with most studies not using a control group, though the use of either regression analysis or matching has increased. Direct costs were generally found to be higher than indirect costs. Direct costs ranged from $242 for a study on out-of-pocket expenditures in Mexico to $11,917 for a study on the cost of diabetes in the USA, while indirect costs ranged from $45 for Pakistan to $16,914 for the Bahamas. In LMICs-in stark contrast to HICs-a substantial part of the cost burden was attributed to patients via out-of-pocket treatment costs. Our regression analysis revealed that direct diabetes costs are closely and positively associated with a country's gross domestic product (GDP) per capita, and that the USA stood out as having particularly high costs, even after controlling for GDP per capita. Studies on the labour market impact of diabetes were almost exclusively confined to HICs and found strong adverse effects, particularly for male employment chances. Many of these studies also took into account the possible endogeneity of diabetes, which was not the case for COI studies.

CONCLUSIONS

The reviewed studies indicate a large economic burden of diabetes, most directly affecting patients in LMICs. The magnitude of the cost estimates differs considerably between and within countries, calling for the contextualization of the study results. Scope remains large for adding to the evidence base on labour market effects of diabetes in LMICs. Further, there is a need for future COI studies to incorporate more advanced statistical methods in their analysis to account for possible biases in the estimated costs.

Cost-of-illness studies of diabetes mellitus: a systematic review

BACKGROUND

Diabetes mellitus (DM) is recognised as a major health problem.

OBJECTIVES

The aims of this study are two-fold: (1) to describe the methods used in the identified cost-of-illness (COI) studies of DM and (2) to summarise their study findings regarding the economic impact of DM.

METHODS

This is a systematic review of MEDLINE and Scopus journal articles reporting the cost of type 1 and/or 2 DM that were published in English from 2007 to 2011. Costs reported in the included studies were converted to US dollars.

RESULTS

The systematic search yielded 30 articles. The studies varied considerably in their study design, perspective and included cost categories. Estimates for the total annual costs of DM ranged from US$141.6 million to US$174 billion; direct costs ranged from US$150 to US$14,060 per patient per year (pppy) whereas indirect costs ranged from US$39.6 to US$7,164 pppy. Inpatient cost was the major contributor to direct cost in half of the studies that included inpatient costs, physician services and medications.

CONCLUSION

There is a considerable economic burden associated with DM. Future research should focus on improving methods of estimating costs, enhancing the interpretation of study findings and facilitating comparisons between studies.

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.

[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.