Performance evaluation of case definitions of type 1 diabetes for health insurance claims data in Japan.

BACKGROUND: No case definition of Type 1 diabetes (T1D) for the claims data has been proposed in Japan yet. This study aimed to evaluate the performance of candidate case definitions for T1D using Electronic health care records (EHR) and claims data in a University Hospital in Japan. METHODS: The EHR and claims data for all the visiting patients in a University Hospital were used. As the candidate case definitions for claims data, we constructed 11 definitions by combinations of International Statistical Classification of Diseases and Related Health Problems, Tenth Revision. (ICD 10) code of T1D, the claims code of insulin needles for T1D patients, basal insulin, and syringe pump for continuous subcutaneous insulin infusion (CSII). We constructed a predictive model for T1D patients using disease names, medical practices, and medications as explanatory variables. The predictive model was applied to patients of test group (validation data), and performances of candidate case definitions were evaluated. RESULTS: As a result of performance evaluation, the sensitivity of the confirmed disease name of T1D was 32.9 (95% CI: 28.4, 37.2), and positive predictive value (PPV) was 33.3 (95% CI: 38.0, 38.4). By using the case definition of both the confirmed diagnosis of T1D and either of the claims code of the two insulin treatment methods (i.e., syringe pump for CSII and insulin needles), PPV improved to 90.2 (95% CI: 85.2, 94.4). CONCLUSIONS: We have established a case definition with high PPV, and the case definition can be used for precisely detecting T1D patients from claims data in Japan.

An exploration of barriers to insulin initiation for physicians in Japan: findings from the Diabetes Attitudes, Wishes And Needs (DAWN) JAPAN study.

OBJECTIVE: Insulin is recommended as an appropriate treatment in type 2 diabetes patients with suboptimal glycemic control; however, its initiation is often delayed. We therefore conducted the DAWN (Diabetes Attitudes, Wishes and Needs) JAPAN study in an attempt to identify specific patient- and physician-related factors which contribute to delay of insulin initiation among Japanese patients with diabetes. In this report, we explored barriers for physicians which prevent timely insulin initiation. METHODS: The DAWN JAPAN study is a multicenter, questionnaire-based survey, conducted between 2004 and 2005. Participating physicians were categorized as follows based on their expertise: Japan Diabetes Society (JDS) certified specialists (n = 77), JDS-affiliated physicians (n = 30), and non-JDS-affiliated physicians (n = 27). To assess physician barriers to insulin initiation, we have used a newly developed 27- item questionnaire. RESULTS: The mean age of patients (n = 11,656) treated by participating physicians was 64.1 years. The mean duration of diabetes was 121.6 months, and their mean HbA1c was 7.5%. Insulin was used in 27.4% of total patients. With regard to physician barriers to insulin initiation, the biggest differences in concerns expressed by JDS-certified specialists and non-JDS-affiliated physicians were observed in the following items with statistical significance: "I do not have staff (nurse, pharmacists) who can assist with explanations" (1.3% vs 55.5%, respectively), "I have concerns about the use of insulin therapy in elderly patients" (38.1% vs 81.5%), and "It is difficult to provide guidance and education on insulin injection to patients" (16.9% vs 55.5%). The mean HbA1c at which physicians responded they would recommend insulin to their patients was 8.7%; however, they would reduce this level to 8.2% if they themselves required insulin. CONCLUSIONS: Our results demonstrated that physicians have concerns about insulin use, and suggested that their concerns can lead to delay of insulin initiation.

Cost-effectiveness analysis of voglibose for prevention of type 2 diabetes mellitus in Japanese patients with impaired glucose tolerance.

UNLABELLED: Aims/Introduction: The objective of this study was to estimate the cost-effectiveness of administering voglibose, in addition to standard care of diet and exercise, compared with standard care alone for high-risk Japanese patients with impaired glucose tolerance. MATERIALS AND METHODS: A Markov model was constructed to estimate the long-term prognosis of individuals with impaired glucose tolerance, in terms of expected medical costs and life expectancy. Transition probabilities were derived from the results of a clinical trial of voglibose, as well as the epidemiological information. Effectiveness was evaluated by life expectancy and only direct costs were considered. The future costs and effectiveness were discounted by 3% per year. RESULTS: Estimated expected lifetime costs for the voglibose administration group and the standard care group was JPY718,724 ($US7598) and JPY1,365,405 ($US14,433), respectively, with voglibose administration resulting in saving of JPY646,681 ($US6836). Estimated life expectancy was 18.672 and 18.073 years, respectively, with life expectancy prolonged by 0.599 years when voglibose was administered together with the standard care. CONCLUSIONS: In order to prevent type 2 diabetes among Japanese patients with impaired glucose tolerance, voglibose with standard care resulted in cost-saving, as well as prolongation of life expectancy, compared with standard care alone. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2010.0052.x, 2010).

Association between postprandial remnant-like particle triglyceride (RLP-TG) levels and carotid intima-media thickness (IMT) in Japanese patients with type 2 diabetes: assessment by meal tolerance tests (MTT).

Our study evaluated the relationship between the pathologic changes associated with atherosclerosis, as primarily represented by postprandial remnant-like lipoproteins and carotid intima-media thickness (IMT), in type 2 diabetic patients. Meal tolerance tests (MTT) were performed in 68 patients with type 2 diabetes. The subjects were divided by pre-meal and 2-h postprandial triglyceride (TG) levels into the normotriglyceridemia (NTG) group; the postprandial hypertriglyceridemia (PHTG) group; and the fasting hypertriglyceridemia (FHTG) group. HOMA-R values were significantly higher in the FHTG group than in the NTG group, with the plasma pre-heparin LPL mass and serum adiponectin levels in the FHTG and PHTG groups significantly lower than in the NTG group. One- and two hour postprandial RLP-TG levels were significantly higher in the PHTG group than in the NTG group, while there was no significant difference in postprandial glucose levels between the two groups. The IMT values were significantly higher in both the FHTG and PHTG groups than in the NTG group. Logistics regression analysis of the 1- and 2-h RLP-TG values using IMT as an induced variable showed the odds ratio for high IMT values to be 5.17 (p < 0.05) for the 1-h RLP-TG values and 3.01 (p = 0.105) for the 2-h RLP-TG values. Our study results suggest that delayed TG metabolism leading to the retention of remnants in type 2 diabetic patients appears to be closely associated with atherosclerosis, and that postprandial hyperlipidemia is an independent risk factor for the early onset of atherosclerosis.

Population-based assessment of familial clustering of diabetic nephropathy in type 1 diabetes.

We determined the magnitude of familial aggregation in the development of diabetic nephropathy (DN) among a population-based cohort of Finnish type 1 diabetic patients. Probands with type 1 diabetes were identified from the nationwide register of all Finnish cases diagnosed during 1965-1979. By 1998, there were 537 families with at least two siblings with type 1 diabetes. These 537 probands and their 616 diabetic siblings were followed for a diagnosis of DN until the end of 2001. We identified 323 cases of DN in these families. If the proband had DN, 38% of the siblings also had DN, whereas out of the diabetic siblings of the probands without DN, only 17% had DN (P = 0.001). Diabetic siblings of the nephropathic probands had a 2.3 times (95% CI 1.4-2.7) higher risk of DN compared with siblings of probands free of DN. The presence of a severe form of DN in the proband increases the risk threefold for diabetic siblings. Sex, the DN of the proband, the age at the onset of diabetes, and parental type 2 diabetes were significant predictors of DN among diabetic siblings. Although the majority of sibpairs with type 1 diabetes are discordant for DN, its presence in one sibling doubles the risk for the other diabetic siblings.

Effects of nateglinide on the elevation of postprandial remnant-like particle triglyceride levels in Japanese patients with type 2 diabetes assessment by meal tolerance test.

To elucidate the role of early insulin response in post-prandial hyperlipidemia, we examined triglyceride (TG) and remnant-like particle triglyceride (RLP-TG) levels, using a meal tolerance test (MTT) with or without the administration of nateglinide (NAT). The MTTs were performed 2 d apart in 36 drug-naive patients with type 2 diabetes who had been hospitalized for glycemic control while receiving diet therapy. Before the second MTT, patients were treated with 90 mg NAT. Treatment with NAT was associated with a significant increase in insulin levels in the treated patients 1 h after the test meal, compared to levels in non-treatment. NAT treatment was also associated with a significant decrease in the level of free fatty acids 1 and 2 h after the meal, and with a significant decrease in plasma glucose levels 1, 2, and 4 h after the meal, compared to those in non-treatment. During the first MTT with NAT non-treatment, 13 patients showed serum TG levels of 200 mg/dL or greater when measured 2 h after the meal. In these 13 patients, NAT administration produced a significant decrease in TG levels 1, 2, and 6 h after the meal, as well as a significant reduction in RLP-TG levels 1 and 2 h after the meal. NAT administration was also associated with significant reductions in area under the curve (DeltaAUC) for TG and RLP-TG. These results suggest that, in a clinical setting, the early insulin response is closely associated with both postprandial glucose and postprandial lipid metabolism in Japanese patients with type 2 diabetes.