A simulation model of the cost of the incidence of IDDM in Spain

Diabetes: cost of illness in Norway

BACKGROUND

Diabetes mellitus places a considerable burden on patients in terms of morbidity and mortality and on society in terms of costs. Costs related to diabetes are expected to increase due to increasing prevalence of type 2 diabetes. The aim of this study was to estimate the health care costs attributable to type 1 and type 2 diabetes in Norway in 2005.

METHODS

Data on inpatient hospital services, outpatient clinic visits, physician services, drugs, medical equipment, nutrition guidance, physiotherapy, acupuncture, foot therapy and indirect costs were collected from national registers and responses to a survey of 584 patients with diabetes. The study was performed with a prevalence approach. Uncertainty was explored by means of bootstrapping.

RESULTS

When hospital stays with diabetes as a secondary diagnosis were excluded, the total costs were €293 million, which represents about 1.4% of the total health care expenditure. Pharmaceuticals accounted for €95 million (32%), disability pensions €48 million (16%), medical devices €40 million (14%) and hospital admissions €21 million (7%). Patient expenditures for acupuncture, physiotherapy and foot therapy were many times higher than expenditure for nutritional guidance. Indirect costs (lost production from job absenteeism) accounted for €70.1 million (24% of the €293 million) and included sick leave (€16.7 million), disability support and disability pensions (€48.2 million) and other indirect costs (€5.3 million). If all diabetes related hospital stays are included (primary- and secondary diagnosis) total costs amounts to €535 million, about 2.6% of the total health care expenditure in Norway.

CONCLUSIONS

Diabetes represents a considerable burden to society in terms of health care costs and productivity losses.

Review of the Uruguayan Kidney Allocation System: the solution to a complex problem, preliminary data

The National Kidney Transplant Program with cadaveric donors is based on centralized and unique waitlist, serum bank, and allocation criteria, approved by Instituto Nacional de Donación y Trasplante (INDT) in agreement with clinical teams. The median donor rates over last 3 years is 20 per million population and the median number of waitlist candidates is 450. The increased number of waiting list patients and the rapid aging of our populations demanded strategies for donor acceptance, candidate assignment, and analysis of more efficient and equitable allocation models. The objectives of the new national allocation system were to improve posttransplant patient and graft survivals, allow equal access to transplantation, and reduce waitlist times. The objective of this study was to analyze variables in our current allocation system and to create a mathematical/simulation model to evaluate a new allocation system. We compared candidates and transplanted patients for gender, age, ABO blood group, human leukocyte agents (HLA), percentage of reactive antibodies (PRA), and waiting list and dialysis times. Only 2 factors showed differences: highly sensitized and patients >65 years old (Bernoulli test). An agreement between INDT and Engineering Faculty yielded a major field of study. During 2008 the data analysis and model building began. The waiting list data of the last decade of donors and transplants were processed to develop a virtual model. We used inputs of candidates and donors, with outputs and structure of the simulation system to evaluate the proposed changes. Currently, the INDT and the Mathematics and Statistics Institute are working to develop a simulation model, that is able to analyze our new national allocation system.

Cost of severe hypoglycaemia in patients with type 1 diabetes in Spain and the cost-effectiveness of insulin lispro compared with regular human insulin in preventing severe hypoglycaemia

OBJECTIVES

To determine the costs of severe hypoglycaemia (SH) in a population of patients with type 1 diabetes mellitus in the Spanish healthcare system and the cost-effectiveness of insulin lispro over regular insulin in preventing SH episodes.

METHODS

A retrospective study of 100 patients in three Spanish health centres was performed. Resource utilisation data were collected only for interventions specifically relating to the hypoglycaemic episode. The direct medical costs determined in the analyses were: costs of hospitalisation, diagnostic tests carried out, costs of treatment administered and other associated costs such as visits to the endocrinologist and re-training in glucose control, transportation and assistance of a care-giver. In addition, indirect costs such as days of lost productivity were measured. The incidence rates of SH for insulin lispro and regular insulin were obtained from the literature. The incremental cost-effectiveness of insulin lispro over regular insulin was calculated.

RESULTS

The overall mean cost per episode of SH was 366 euro, comprised of 65.4% direct costs and 35.6% indirect costs. The largest cost was for hospitalisation at 183 euro per episode. The SH episodes incidence rates for 100 patients per year were 33 and 73 for insulin lispro and 48 (p < 0.05) and 117 (p < 0.01) for regular insulin, in the two clinical trials found in the literature. The additional cost to prevent one episode of SH with insulin lispro over regular insulin ranged from 277 euro to insulin lispro dominance.

CONCLUSIONS

Severe hypoglycaemia has a significant impact on the total cost of diabetes. The use of insulin lispro is associated with reductions in annual costs because of SH and, possibly, the overall effect may be cost neutral or cost saving when total costs are considered. The cost of SH should be included in the analysis of total socio-economic burden of diabetes.

Clinical trial optimization: Monte Carlo simulation Markov model for planning clinical trials recruitment

INTRODUCTION

The patient recruitment process of clinical trials is an essential element which needs to be designed properly.

METHODS

In this paper we describe different simulation models under continuous and discrete time assumptions for the design of recruitment in clinical trials.

RESULTS

The results of hypothetical examples of clinical trial recruitments are presented. The recruitment time is calculated and the number of recruited patients is quantified for a given time and probability of recruitment. The expected delay and the effective recruitment durations are estimated using both continuous and discrete time modeling.

CONCLUSION

The proposed type of Monte Carlo simulation Markov models will enable optimization of the recruitment process and the estimation and the calibration of its parameters to aid the proposed clinical trials. A continuous time simulation may minimize the duration of the recruitment and, consequently, the total duration of the trial.

La diabetes mellitus en España: mortalidad, prevalencia, incidencia, costes económicos y desigualdades

OBJECTIVE

Describing the situation of diabetes mellitus (DM) in Spain from a public health perspective.

MATERIAL AND METHOD

manual review of books and other documents on diabetes mellitus in Spain was conducted. In addition, a specific research of articles published using MeSH terms diabetes mortality, prevalence, incidence, cost, inequalities and Spain was conducted in Medline through Internet (PubMed). Minimun Basic Data Set was utilized as source for complication description by Communities Autonomus.

RESULTS

DM is one of the leading cause of mortality and the third one in women. With regard to Autonomous Communities, Canary Islands, Ceuta y Melilla and Andalusia show the greatest mortality with a downward trend. Diabetics present greater mortality than non diabetic patients, being complications the main cause of the over-mortality, especially ischemic heart disease. Estimations of prevalence for DM2 range from 4.8% to 18.7% and for DM1, from .08% to .2%. In pregnancy, it has been noted a prevalence ranging from 4.5% to 16.1%. With respect to incidence per year, it is estimated a range from 146 to 820 per 100,000 inhabitants for DM2 and a range from 10 to 17 new cases annually per 100,000 inhabitants for DM1. Costs for DM1 show very different results, averaging between 1,262 and 3,311 euro per people and year. There are differences for DM2 costs as well, averaging between 381 and 2,560 euro per patient and year. Total costs estimated range from 758 to 4,348 euro per person and year. Relationship between a low socioeconomic level (LSL) and DM2 risk has been proved. Moreover, it has been noted that the less LSL the worse is the disease control, coupled with a greater frequency and more frequent factors of DM2 risk.

CONCLUSIONS

The knowledge about the situation of the DM as a Public Health problem in Spain is limited. Mortality data available does not gather its real magnitude, and prevalence, incidence, costs and inequalities research are very poor and hardly comparable. In spite of this degree of incertitude, we can state that DM is an important public health problem with a continuous increase, especially DM2, if the appropriate prevention and control measures are not taken.

Economic burden on families of childhood type 1 diabetes in urban Sudan

The aims of this study were to estimate the direct costs of childhood diabetes in a low income country, Sudan, and to assess the effectiveness of care paid for by the families. For this purpose, socio-economic and demographic data on families were obtained from the parents of 147 children with type 1 diabetes, attending public or private clinics in Khartoum State, Sudan. The median annual income of the families of diabetic children was US dollars (US$) 1222 (range 0-14,338) of which 16% was received as financial help from relatives and friends. The median annual expenditure of diabetes care was US$ 283 per diabetic child of which 36% was spent on insulin. Of the family expenditure on health, 65% was used for the diabetic child. Families of diabetic children who were attending private clinics had a significantly higher total expenditure on health and home blood glucose monitoring than those who were attending the public clinics. However, there was no difference in total income between the two groups and glycaemic control was poor in 86% of the patients, regardless of whether care was being given by private or public clinics. The occurrence of the disease and its poor control appeared to exert a negative impact on the school performance of the diabetic child. In conclusion, the low direct costs reflect the minimal care given to the diabetic patients. Under the present economic conditions, families pay a considerable part of their income to sponsor the health of their diabetic children and receive little support other than that from relatives and friends. The present organization of diabetes care does not provide the patient with empowerment, knowledge and self-care ability. Well-trained diabetic teams and education programs may improve this situation.

Costes económicos asociados a la diabetes tipo 1

OBJECTIVE

The objective of our study was to determinate the health resource utilization and economic cost associated to diabetes in a patient group with type 1 diabetes.

PATIENTS AND METHODS

We designed a cross-sectional study that involved 71 type 1 diabetes patients (59.4% women) with 29.2 +/- 12.2 years old mean age and 10.5 +/- 7.9 years of diabetes evolution attended in Endocrinology Service of Puerta del Mar Hospital in Cádiz. Direct and indirect cost associated to diabetes during a year period were determinated by information obtained from patient medical history and hospital, emergency, primary care and medical inspection of social insurance databases.

RESULTS

Type 1 diabetes patients presented a total cost associated to diabetes of 3.311 euros/patient/year (95% IC: 2.202-4.420 euros/patient/year). Direct cost (2.104 euros/patient/year; 95% IC: 1.825-2.383 euros/patient/year) was higher than indirect cost (1.250 euros/patient/year; 95% IC: 291-2.225 euros/patient/year). Multiple regression analysis showed an independent association between total cost associated to diabetes (dependent variable) and variables number of hospitalizations related to diabetes (p = 0.006), pensioner situation (p = 0.02) and micro and macrovascular complications (p = 0.001).

CONCLUSIONS

We conclude that economic cost associated to type 1 diabetes is important and presents a notable and independent increase with hospitalizations related to diabetes, pensioner situation and micro and macrovascular complications.

Model-Based Evaluation of Diabetic Foot Prevention Strategies in Austria

Diabetes mellitus affects approximately 171 million individuals worldwide. The costs of the adult form of diabetic mellitus account for up to 6% of total health care expenditures in industrialized countries. About 25% of these diabetics develop disabling and most painful foot complications accounting for about 17% of the direct lifetime costs. Diabetic foot prevention programs have been recently introduced in some Austrian federal states to meet the diabetic health targets of the Austrian Health Plan and the St. Vincent Declaration. We developed a new age-group specific Markov model combined with a Monte Carlo simulation model to help policymakers analyze the cost-effectiveness of such programs compared to the status quo in terms of incremental costs per quality-adjusted life years gained (QALY). The Markov model revealed that diabetic foot prevention programs were cost saving when targeted at patients at high risk and mainly cost-effective when targeted at patients with mild symptoms. The Monte Carlo simulation showed that only large scope prevention programs would fulfill the specified reductions in the number of diabetic foot complications as defined in the Austrian Health Plan and the St. Vincent Declaration. Our results clearly indicate the enormous impact of diabetic foot prevention programs.

Cost-of-illness studies in diabetes mellitus

Several cost-of-illness (COI) studies related to diabetes mellitus have been performed over the last three decades. This review examines the results of these COI studies, identifies the strengths and limitations of the various methods utilised, and suggests future research that will help determine the economic burden of diabetes more accurately. Diabetes imposes a large economic burden on society. The economic cost of diabetes is estimated to be as much as dollars US 100 billion per year in the US alone (1997 values). This estimated cost has increased notably over time, primarily due to price inflation and the increasing prevalence of diabetes. Differing methodologies have significantly influenced the cost estimates and made comparisons between COI studies problematic. For example, early reports tended to rely exclusively on data where diabetes was listed as the primary diagnosis or reason for healthcare use. To better capture the costs associated with diabetes-related complications, later studies have included costs related to diabetes as a secondary or tertiary diagnosis using the attributable risk methodology. Given the types of long-term complications that are associated with diabetes, attempts at capturing these secondary costs are appropriate. However, estimates of attributable risk can be limited by the epidemiological data currently available. The tremendous economic burden of diabetes makes the disease an important clinical and public health problem. In order to formulate an effective response to this problem, it is important to track future economic trends as healthcare delivery, morbidity and mortality patterns evolve. Future research efforts should focus on refining methods to estimate costs, improving the interpretation of study findings, and facilitating comparisons between studies.

An antidiabetic thiazolidinedione induces eccentric cardiac hypertrophy by cardiac volume overload in rats

1. To assess the involvement of volume overload in the development of cardiac hypertrophy during treatment with an antidiabetic thiazolidinedione, changes in cardiac anatomy and parameters of cardiac volume overload were evaluated in female Sprague-Dawley rats treated with the thiazolidinedione derivative T-174. 2. Two week administration of T-174 (13 and 114 mg/kg per day) increased absolute and relative heart weights by 11-24%, demonstrating the development of cardiac hypertrophy. There was no evidence of oedema in hearts from treated rats. 3. Both plasma and blood volumes were increased in T-174-treated rats without any changes in systolic blood pressure and heart rate, whereas haematocrit was decreased. In accordance with the existence of volume overload, both left ventricular end-diastolic pressure and right atrial pressure were increased. Morphometric analysis of hearts revealed that T-174 induced eccentric heart hypertrophy, as characterized by a small increase in wall thickness and a large increase in the chamber volume, which is characteristic of volume overload. Volume overload is suggested as the possible trigger mechanism because blood volume expansion preceded cardiac hypertrophy and there was a high correlation between heart weight and blood volume. 4. T-174-treated streptozotocin-induced diabetic rats also exhibited blood volume expansion and cardiac hypertrophy. 5. These findings suggest that cardiac volume overload is induced by plasma volume expansion and contributes to the development of eccentric cardiac hypertrophy during treatment with antidiabetic thiazolidinediones. Although thiazolidinediones are insulin-sensitizing agents, these cardiac effects are likely to be mediated independently of insulin.

Increase in the incidence of type 1 diabetes mellitus in children in three cities in Poland, 1987-1999

The aim of this study was to evaluate the trends in the incidence of type 1 diabetes mellitus (DM) in children aged 0-14 years between 1987 and 1999 in three cities in Poland. The study area comprised the provinces of Cracow and Wroclaw and the city of Warsaw. The data were collected prospectively on the basis of the register within the framework of the EURODIAB study up till 1997 and then within the project of the Ministry of Health. During the 13 years of the study period, 766 children (380 girls, 386 boys) with newly diagnosed type 1 DM were identified. The overall age-standardized incidence rates were 8.4/100,000 standardized population/year (95% CI 7.4-9.3) for Cracow province, 6.5/100,000/year (95% CI 5.6-7.4) for Wroclaw province and 7.9/100,000/year (95% CI 6.9-8.8) for Warsaw. A significant trend of increase for children aged 0-14 years was found in the three cities. The analysis of the trend in age subgroups showed a significant increase in incidence in all three age subgroups in Warsaw and Cracow province (0-4 year-old children, p <0.05; 5-9 year-olds, p <0.001 in Cracow province, p <0.05 in Warsaw, and in 10-14 year-olds, p <0.05 in Cracow province, p <0.005 in Warsaw). In the Wroclaw province a significant increase was observed in children aged 0-4 years (p <0.05) and 5-9 years (p <0.001). In children aged 10-14 years the increase was not statistically significant. The results of our study showed that the incidence of type 1 DM in children is rising. A similar phenomenon is occurring in many other countries. The greatest increase of incidence was observed in the 5-9 year-old subgroup of children in Cracow and Wroclaw provinces and in children aged 10-14 years in Warsaw. The incidence rates in excess of 9.0/100,000 per year observed since 1996 have placed Poland in the group of countries with low to medium incidence.

[Epidemiology of diabetes and its non-coronary complications]

Diabetes mellitus is among the diseases with great impact on health and society, not only for its high prevalence but also for its chronic complications and high mortality. The most precise method to investigate the prevalence of diabetes is by oral glucose tolerance testing. In Spain, the prevalence of diabetes in the 30-65 year-old population is estimated to be 6.5% among 30-to-65- year old, and 10.3% among the 30-to-89 year-old population. The ratio of known to unknown diabetes ranges from 1:3 to 2:3. The incidence of diabetes mellitus type 2 in Spain is 8/1000 persons per year, and the incidence of type 1 is 11 to 12 cases per 100,000 persons per year. The prevalence of chronic complications varies according to type of diabetes, time since onset and degree of metabolic control: neuropathy 25%, retinopathy 32% and nephropathy 23%. Diabetes is one of the most important causes of death in Spain, occupying third place for women and seventh for men.

How cost-effective is the treatment of dyslipidemia in patients with diabetes but without cardiovascular disease?

OBJECTIVE

Epidemiological studies have shown that the risk of myocardial infarction (MI) in diabetic patients without cardiovascular disease (CVD) is comparable to the risk of MI in patients with CVD. We used a validated Markov model to compare the long-term costs and benefits of treating dyslipidemia in diabetic patients without CVD versus treating CVD patients without diabetes in the U.S. The generalizability and robustness of these results were also compared across six other countries (Canada, France, Germany, Italy, Spain, and the U.K.).

RESEARCH DESIGN AND METHODS

With use of the Cardiovascular Disease Life Expectancy Model, cost effectiveness simulations of simvastatin treatment were performed for men and women who were 40-70 years of age and had dyslipidemia. We forecast the long-term risk reduction in CVD events after treatment. On the basis of the Scandinavian Simvastatin Survival Study results, we assumed a 35% reduction in LDL cholesterol and an 8% rise in HDL cholesterol.

RESULTS

In the U.S., treatment with simvastatin for CVD patients without diabetes was cost-effective, with estimates ranging from $8,799 to $21,628 per year of life saved (YOLS). Among diabetic individuals without CVD, lipid therapy also appeared to be cost-effective, with estimates ranging from $5,063 to $23,792 per YOLS. In the other countries studied, the cost effectiveness of treating diabetes in the absence of CVD was comparable to the cost effectiveness of treating CVD in the absence of diabetes.

CONCLUSIONS

Among diabetic men and women who do not have CVD, lipid therapy is likely to be as effective and cost-effective as treating nondiabetic individuals with CVD.

Excess costs of medical care 1 and 8 years after diagnosis of diabetes: estimates from young and middle-aged incidence cohorts in Sweden

To analyze the excess costs of medical care during the first decade after diabetes diagnosis, we surveyed two national incidence cohorts who contracted diabetes at age of 15-34 years and matched control groups from the general population of Sweden. Ninety percent of the diabetic subjects were on insulin treatment. Data on healthcare utilization and use of glucose lowering drugs and medical devices were collected via a questionnaire mailed to a recent cohort 1 year after diagnosis and a previously registered cohort 8 years after diagnosis. Costing was based on average national costs of hospital inpatient and out-patient care, an original study of daycare costs, and sales prices of the National Corporation of Swedish Pharmacies. One year after diabetes diagnosis, the annual excess costs of care were US$4743 among men and US$4976 among women (1997 prices). Hospital inpatient care accounted for more than 50% of the excess costs. Eight years after diagnosis, the excess costs were US$2010 among men and US$2734 among women. The higher costs for women were mainly related to hospital out-patient care, but also to more intensive self-monitoring. We conclude that diabetes in young and middle-aged people is a major economic challenge even before significant complications may have developed.

Selecting a decision model for economic evaluation: a case study and review

The increased use of modelling techniques as a methodological tool in the economic evaluation of health care technologies has, in the main, been limited to two approaches--decision trees and Markov chain models. The former are suited to modelling simple scenarios that occur over a short time period, whilst Markov chain models allow longer time periods to be modelled, in continuous time, where the timing of an event is uncertain. In the context of economic evaluation, a less well developed technique is discrete event simulation, which may allow even greater flexibility. Taking the economic evaluation of adjuvant therapies for breast cancer as an illustrative example, the process of building a decision tree, a Markov chain model, and a discrete event simulation model are described. The potential benefits and problems of each approach are discussed. The suitability of the modelling techniques to economic evaluations of health care programmes in general is then discussed. This section aims to illustrate the areas in which the alternative modelling methods may be most appropriately employed.