An economic analysis of captopril in the treatment of diabetic nephropathy. The Collaborative Study Group

Modeling Chronic Kidney Disease in Type 2 Diabetes Mellitus: A Systematic Literature Review of Models, Data Sources, and Derivation Cohorts

INTRODUCTION

As novel therapies for chronic kidney disease (CKD) in type 2 diabetes mellitus (T2DM) become available, their long-term benefits should be evaluated using CKD progression models. Existing models offer different modeling approaches that could be reused, but it may be challenging for modelers to assess commonalities and differences between the many available models. Additionally, the data and underlying population characteristics informing model parameters may not always be evident. Therefore, this study reviewed and summarized existing modeling approaches and data sources for CKD in T2DM, as a reference for future model development.

METHODS

This systematic literature review included computer simulation models of CKD in T2DM populations. Searches were implemented in PubMed (including MEDLINE), Embase, and the Cochrane Library, up to October 2021. Models were classified as cohort state-transition models (cSTM) or individual patient simulation (IPS) models. Information was extracted on modeled kidney disease states, risk equations for CKD, data sources, and baseline characteristics of derivation cohorts in primary data sources.

RESULTS

The review identified 49 models (21 IPS, 28 cSTM). A five-state structure was standard among state-transition models, comprising one kidney disease-free state, three kidney disease states [frequently including albuminuria and end-stage kidney disease (ESKD)], and one death state. Five models captured CKD regression and three included cardiovascular disease (CVD). Risk equations most commonly predicted albuminuria and ESKD incidence, while the most predicted CKD sequelae were mortality and CVD. Most data sources were well-established registries, cohort studies, and clinical trials often initiated decades ago in predominantly White populations in high-income countries. Some recent models were developed from country-specific data, particularly for Asian countries, or from clinical outcomes trials.

CONCLUSION

Modeling CKD in T2DM is an active research area, with a trend towards IPS models developed from non-Western data and single data sources, primarily recent outcomes trials of novel renoprotective treatments.

Multiple fluorescence quenching effects mediated fluorescent sensing of captopril Based on amino Acids-Derivative carbon nanodots

Carbon nanodots (CNDs) were facilely synthesized through a pyrolysis procedure with histamine, an amino acid rich in element carbon and nitrogen, being the precursor. Taking advantage of the favorable fluorescence performance of CNDs, a multiple fluorescence quenching effects mediated fluorescent sensor was established for captopril (CAP) detection. MnO₂ NPs were firstly combined with CNDs via electrostatic attraction and subsequently quenched the fluorescence. The quenching mechanisms were concluded to be the combined effects of fluorescence resonance energy transfer (FRET) and inner filtration effect (IFE). Subsequently CAP triggered a unique redox reaction and decomposed the quencher so that renewed the fluorescence. Hence, the sensitive and selective detection of CAP was achieved through the indication of fluorescence recovery efficiency. A proportional range of 0.4 ∼ 60 μmol L^-1 with the LOD of 0.31 μmol L^-1 was obtained. The sensor was further applied to the real sample detection and the satisfactory results revealed the practical value of CNDs. The facile synthesis of CNDs and brand-new sensing mechanism made it a novel fluorescent method and could improve the analysis of CAP.

Economic Modelling of Chronic Kidney Disease: A Systematic Literature Review to Inform Conceptual Model Design

BACKGROUND

Chronic kidney disease (CKD) is a progressive condition that leads to irreversible damage to the kidneys and is associated with an increased incidence of cardiovascular events and mortality. As novel interventions become available, estimates of economic and clinical outcomes are needed to guide payer reimbursement decisions.

OBJECTIVE

The aim of the present study was to systematically review published economic models that simulated long-term outcomes of kidney disease to inform cost-effectiveness evaluations of CKD treatments.

METHODS

The review was conducted across four databases (MEDLINE, Embase, the Cochrane library and EconLit) and health technology assessment agency websites. Relevant information on each model was extracted. Transition and mortality rates were also extracted to assess the choice of model parameterisation on disease progression by simulating patient's time with end-stage renal disease (ESRD) and time to ESRD/death. The incorporation of cardiovascular disease in a population with CKD was qualitatively assessed across identified models.

RESULTS

The search identified 101 models that met the criteria for inclusion. Models were classified into CKD models (n = 13), diabetes models with nephropathy (n = 48), ESRD-only models (n = 33) and cardiovascular models with CKD components (n = 7). Typically, published models utilised frameworks based on either (estimated or measured) glomerular filtration rate (GFR) or albuminuria, in line with clinical guideline recommendations for the diagnosis and monitoring of CKD. Generally, two core structures were identified, either a microsimulation model involving albuminuria or a Markov model utilising CKD stages and a linear GFR decline (although further variations on these model structures were also identified). Analysis of parameter variability in CKD disease progression suggested that mean time to ESRD/death was relatively consistent across model types (CKD models 28.2 years; diabetes models with nephropathy 24.6 years). When evaluating time with ESRD, CKD models predicted extended ESRD survival over diabetes models with nephropathy (mean time with ESRD 8.0 vs. 3.8 years).

DISCUSSION

This review provides an overview of how CKD is typically modelled. While common frameworks were identified, model structure varied, and no single model type was used for the modelling of patients with CKD. In addition, many of the current methods did not explicitly consider patient heterogeneity or underlying disease aetiology, except for diabetes. However, the variability of individual patients' GFR and albuminuria trajectories perhaps provides rationale for a model structure designed around the prediction of individual patients' GFR trajectories. Frameworks of future CKD models should be informed and justified based on clinical rationale and availability of data to ensure validity of model results. In addition, further clinical and observational research is warranted to provide a better understanding of prognostic factors and data sources to improve economic modelling accuracy in CKD.

Prevention of renal failure in Chinese patients with newly diagnosed type 2 diabetes: A cost-effectiveness analysis

Aims/Introduction

Diabetic kidney disease (DKD) is the second leading cause (16.4%) of end‐stage renal disease in China. The current study assessed the cost‐effectiveness of preventing DKD in patients with newly diagnosed type 2 diabetes from the Chinese healthcare perspective.

Materials and Methods

A lifetime Markov decision model was developed according to the disease course of DKD. Patients with newly diagnosed type 2 diabetes might receive treatment according to one of the following three strategies: (i) “do nothing” strategy (control strategy); (ii) treatment with angiotensin‐converting enzyme inhibitors and angiotensin II receptor blockers (universal strategy); (iii) or screening for microalbuminuria followed by angiotensin‐converting enzyme inhibitor/angiotensin II receptor blocker treatment (screening strategy). Clinical and utility data were obtained from the published literature. Direct medical costs and resource utilization in the Chinese healthcare setting were considered. Sensitivity analyses were undertaken to test the impact of a range of variables and assumptions on the results.

Results

Compared with the control strategy, both the screening and universal strategies were cost‐saving options that showed lower costs and better health benefits. The incremental cost‐effectiveness ratio of the universal strategy over the screening strategy was US $30,087 per quality‐adjusted life‐year, which was higher than the cost‐effectiveness threshold of China. The sensitivity analyses showed robust results, except for the probability of developing macroalbuminuria from microalbuminuria.

Conclusions

Screening for microalbuminuria could be a cost‐saving option for the prevention of DKD in the Chinese setting.

Going Upstream: Coordination to Improve CKD Care

Care coordination for patients with chronic kidney disease has been shown to be effective in improving outcomes and reducing costs. However, few patients with CKD benefit from this systematic management of their kidney disease and other medical conditions. As a result, outcomes for patients with kidney disease are not optimal, and their cost of care is increased. For those patients who transition to kidney failure treatment in the United States, the transition does not go as well as it could. The effectiveness of treatments to delay progression of kidney disease in contemporary clinical practice does not match the efficacy of these treatments in clinical trials. Conservative care for kidney disease, which should be an option for patients who are very old and very sick, is not considered often enough or seriously enough. Opportunities for early and even pre-emptive transplantation are missed, as are opportunities for home dialysis. The process of dialysis access creation is rarely optimal. The consequence is care which is not as good as it could be, and much more expensive than it should be. We describe our initial efforts to implement care coordination for chronic kidney disease in routine clinical care and attempt to project some of the benefits to patients and the cost savings.

Cost implications of caring for chronic kidney disease: are interventions cost-effective?

Recent data suggest a large, rising burden of chronic kidney disease (CKD) in the general population and rising expenses associated with it. In 2007, CKD contributed 27.6% of costs and CKD subjects constituted 9.8% of the population. Between 1993 and 2007, overall Medicare costs nearly doubled and CKD-associated costs increased about 5-fold. The Medicare cost of end-stage renal disease has risen from $12.2 in 2000 to $20.8 billion in 2007. This review examines cost-effectiveness of prevention and treatment of CKD. Mathematical derivation of savings associated with prevention of CKD is not feasible because of dearth of data. However, examination of various factors that would affect such a hypothetical derivation indicates that prevention of CKD is cost-effective. Better data enable modeling of gross savings of slowing the progression of CKD. Data suggest that if at the beginning of the current decade, the rate of decline in GFR decreased by 10% and 30% in every patient with GFR of 60 mL/min/1.73 m(2) or less the gross direct cumulative health care savings over the next 10 years amount to $18.56 and $60.61 billion, respectively. Additional benefits accrue as a result of diminishing disability and gain in productivity. The analysis suggests that prevention and slowing progression of CKD is cost-effective.

Renal Health Models in Latin America: Development of National Programs of Renal Health

PURPOSE

To verify the actions and degree of progress achieved in countries of Latin America and the Caribbean in the implementation of the Sustainable and Tenable Renal Health Model promoted by the Latin American Society of Nephrology and Hypertension (SLANH), together with local societies and the participation of the Pan-American Health Organization. (PAHO/WHO).

METHOD

The implementation of workshops (e.g., "Toward a Sustainable and Tenable Renal Health Model") in each country involving health ministries, social security agencies, PAHO, scientific societies, medical organizations, and NGOs, among others, as well as start-up conferences with a special emphasis on local problems. Working teams will state the bases for planning, programming and evaluation in the Logical Framework Matrix and Matrix of Activities and Resources in the First Level of Care. The signature of the document "Declaration" with commitments undertaken by both public and private parties and a work schedule are required.

RESULTS

So far, eleven countries in the region have conducted workshops and started activity in the frame of the Model/Program of Renal Health, which articulates the traditional vertical programs and generates a cross-program in the First Level of Care. Its components and strategies make up a cost-efficient control of cardiovascular, renal and endocrine-metabolic health.

CONCLUSION

The Renal Health Model and its program is being built into public health care policies of countries in Latin America and the Caribbean and adapted to the needs of each country with an increasing acceptance on the part of health care professionals. It should not be implemented in isolation but within the framework of non transmissible diseases.

Cardiac mitochondrial function and tissue remodelling are improved by a non-antihypertensive dose of enalapril in spontaneously hypertensive rats

Renal and cardiac benefits of renin-angiotensin system inhibition exceed blood pressure (BP) reduction and seem to involve mitochondrial function. It has been shown that RAS inhibition prevented mitochondrial dysfunction in spontaneously hypertensive rats (SHR) kidneys. Here, it is investigated whether a non-antihypertensive enalapril dose protects cardiac tissue and mitochondria function. Three-month-old SHR received water containing enalapril (10 mg/kg/day, SHR+Enal) or no additions (SHR-C) for 5 months. Wistar-Kyoto rats (WKY) were normotensive controls. At month 5, BP was similar in SHR+Enal and SHR-C. In SHR+Enal and WKY, heart weight and myocardial fibrosis were lower than in SHR-C. Matrix metalloprotease-2 activity was lower in SHR+Enal with respect to SHR-C and WKY. In SHR+Enal and WKY, NADH/cytochrome c oxidoreductase activity, eNOS protein and activity and mtNOS activity were higher and Mn-SOD activity was lower than in SHR-C. In summary, enalapril at a non-antihypertensive dose prevented cardiac hypertrophy and modifies parameters of cardiac mitochondrial dysfunction in SHR.

Cost-utility analysis of antihypertensive combination therapy in Japan by a Monte Carlo simulation model

The objective of the present study was to analyze the cost-effectiveness of lifetime antihypertensive therapy with angiotensin II receptor blocker (ARB) monotherapy, calcium channel blocker (CCB) monotherapy, or ARB plus CCB (ARB+CCB) combination therapy in Japan. Based on the results of large-scale clinical trials and epidemiological data, we constructed a Markov model for patients with essential hypertension. Our Markov model comprised coronary heart disease (CHD), stroke, and progression of diabetic nephropathy submodels. Based on this model, analysis of the prognosis of each patient was repeatedly conducted by Monte Carlo simulation. The three treatment strategies were compared in hypothetical 55-year-old patients with systolic blood pressure (SBP) of 160 mmHg in the absence and presence of comorbid diabetes. Olmesartan medoxomil 20 mg/d was the ARB and azelnidipine 16 mg/d the CCB in our model. On-treatment SBP was assumed to be 125, 140, and 140 mmHg in the ARB+CCB, ARB alone, and CCB alone groups, respectively. Costs and quality-adjusted life years (QALYs) were discounted by 3%/year. The ARB+CCB group was the most cost-effective both in male and female patients with or without diabetes. In conclusion, ARB plus CCB combination therapy may be a more cost-effective lifetime antihypertensive strategy than monotherapy with either agent alone.

A cost-effectiveness analysis of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in diabetic nephropathy

The aim of this study was to estimate the cost-effectiveness of renin-angiotensin-aldosterone system blockers in patients with diabetic nephropathy. A cost-effectiveness analysis was performed based on a meta-analysis of studies investigating the effect of angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) as part of a treatment regimen on the incidence of end-stage renal disease (ESRD) in patients with diabetic nephropathy. The primary outcome was the cost to prevent 1 patient from developing ESRD. Cost analysis was performed from a third-party payer perspective in 2006 US dollars. As part of a treatment regimen, ARBs significantly reduced the incidence of ESRD and doubling of serum creatinine concentration (P<.05) but not total mortality. The cost to prevent 1 patient from developing ESRD was $31,729 (95% confidence interval, $19,443-$85,442; P<.01), $189,190 (P=.13) and $51,585 (P=.068) for patients receiving ARBs, ACE inhibitors, or either of them, respectively. This study demonstrates that blocking the RAAS, which delays the progression to ESRD, appears to be cost-effective. The current analysis favors ARBs in terms of cost-effectiveness.

Irbesartan treatment of patients with type 2 diabetes, hypertension and renal disease: a UK health economics analysis

The objective of the study was to determine the impact of irbesartan treatment on life expectancy (LE), costs and progression to end-stage renal disease (ESRD) in hypertensive type 2 diabetes patients. A peer-reviewed and published Markov model was used to simulate progression from microalbuminuria to overt nephropathy, doubling of serum creatinine, ESRD and all-cause mortality in hypertensive patients with type 2 diabetes. Three treatment strategies were evaluated: (i) 'control' regimen of conventional antihypertensive therapy (excluding angiotensin-converting enzyme inhibitors, angiotensin-2-receptor antagonists and dihydropyridine calcium-channel blockers), (ii) 'early irbesartan' 300 mg daily and (iii) 'late irbesartan' 300 mg daily (started when overt nephropathy developed). Transition probabilities determining nephropathy progression were taken from the Irbesartan in Reduction of Microalbuminuria-2 study, Irbesartan in Diabetic Nephropathy Trial and other published sources. Outcomes were projected over 25 years. The mean +/- SD cumulative incidence of ESRD was reduced by 8.8% +/- 0.6 and 12.4% +/- 0.7 in patients treated with early irbesartan compared with late irbesartan and control respectively. Early irbesartan treatment improved undiscounted LE by 1.38 +/- 0.08 years (discounted: 0.81 +/- 0.04 years) compared with late irbesartan and 1.41 +/- 0.08 years (discounted: 0.83 +/- 0.04 years) compared with control. Early irbesartan treatment was projected to save (mean +/- SD) pounds 2310 +/- 327 and pounds 3801 +/- 327 over patient lifetimes compared with late irbesartan and control respectively. Irbesartan treatment is predicted to improve survival and reduce costs in hypertensive patients with type 2 diabetes and microalbuminuria compared with 'control'. Early irbesartan treatment is more effective than late irbesartan. Irbesartan is a valuable treatment option in this patient group in a UK setting.

WITHDRAWN: Angiotensin converting enzyme inhibitors in normotensive diabetic patients with microalbuminuria

BACKGROUND

Renal disease is a serious complication of diabetes mellitus.

OBJECTIVES

To examine whether the progression of early diabetic renal disease to end-stage renal failure may be slowed by the use of angiotensin converting enzyme inhibitors for reasons other than their antihypertensive properties, so that they have value in the treatment of normotensive diabetics with microalbuminuria.

SEARCH STRATEGY

Medline was searched for English language reviews and randomised controlled trials. Personal reference lists, and reference lists of retrieved studies were also used.

SELECTION CRITERIA

Randomised controlled trials with separate identifiable results for initially normotensive diabetic patients, who received angiotensin converting enzyme inhibitors for at least one year and were compared with controls.

DATA COLLECTION AND ANALYSIS

Meta-analyses were performed on the results of 12 randomised controlled trials with a variety of patient inclusion and exclusion criteria. One further study met all conditions for inclusion but did not provide data in useable form for meta-analyses.

MAIN RESULTS

Albumin excretion rate fell for patients on angiotensin converting enzyme inhibition in 12 of the 13 studies but did so for only two of the 13 groups on placebo. Treatment provided a significant reduction in albumin excretion rate in both insulin dependent diabetes mellitus and non insulin dependent diabetes mellitus. Treatment with either captopril, enalapril or lisinopril reduced albumin excretion rate in comparison with control patients.A significantly greater lowering of blood pressure was experienced by initially normotensive patients in the angiotensin converting enzyme inhibitor than in the placebo group. Average glycosylated haemoglobin fell a little in the treated patients and rose in the controls, the difference being just significant. The difference in changes in glomerular filtration rate did not reach statistical significance.

AUTHORS' CONCLUSIONS

Inhibition of angiotensin converting enzyme can arrest or reduce the albumin excretion rate in microalbuminuric normotensive diabetics, as well as reduce or prevent an increase in blood pressure. But, given the drop in blood pressure in patients on angiotensin converting enzyme inhibitors, it is not certain that the reduction of albumin excretion rate is due to a separate renal effect. A direct link with postponement of end-stage renal failure has not been demonstrated. There appear to be no substantial side effects.

Treatment options for type 2 diabetes in adolescents and youth: a study of the comparative efficacy of metformin alone or in combination with rosiglitazone or lifestyle intervention in adolescents with type 2 diabetes

Despite the increased prevalence of type 2 diabetes mellitus (T2DM) in the pediatric population, there is limited information about the relative effectiveness of treatment approaches. This article describes the rationale and design of a National Institutes of Health-sponsored multi-site, randomized, parallel group clinical trial designed to test the hypothesis that aggressive reduction in insulin resistance early in the course of T2DM is beneficial for prolongation of glycemic control, as well as improvement in associated abnormalities and risk factors. Specifically, the trial compares treatment with metformin with two alternate approaches, one pharmacologic (combining metformin treatment with rosiglitazone) and one combining metformin with an intensive lifestyle intervention program. The Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study recruits 800 patients over a 4-yr period and follows them for a minimum of 2 yr and maximum of 6 yr. Patients are 10-17 yr of age, within 2 yr of diagnosis of diabetes at the time of randomization, lack evidence of autoimmunity, and have sustained C-peptide secretion. The primary outcome is time to loss of glycemic control, defined as a hemoglobin A1c >8% for 6 consecutive months. Secondary outcomes include the effect of the alternative treatments on insulin secretion and resistance, body composition, nutrition, physical activity and fitness, cardiovascular risk monitoring, microvascular complications, quality of life, depression, eating pathology, and resource utilization. TODAY is the first large-scale, systematic study of treatment effectiveness for T2DM in youth. When successfully completed, this study will provide critical new information regarding the natural history of T2DM in youth, the benefits of initiating early aggressive treatment in these patients, and the efficacy of delivering an intensive and sustained lifestyle intervention to children with T2DM.

TODAY Study Group, Zeitler P, Epstein L, Grey M, Hirst K, Kaufman F, Tamborlane W, Wilfley D. Treatment options for type 2 diabetes in adolescents and youth: a study of the comparative efficacy of metformin alone or in combination with rosiglitazone or lifestyle intervention in adolescents with type 2 diabetes

Despite the increased prevalence of type 2 diabetes mellitus (T2DM) in the pediatric population, there is limited information about the relative effectiveness of treatment approaches. This article describes the rationale and design of a National Institutes of Health-sponsored multi-site, randomized, parallel group clinical trial designed to test the hypothesis that aggressive reduction in insulin resistance early in the course of T2DM is beneficial for prolongation of glycemic control, as well as improvement in associated abnormalities and risk factors. Specifically, the trial compares treatment with metformin with two alternate approaches, one pharmacologic (combining metformin treatment with rosiglitazone) and one combining metformin with an intensive lifestyle intervention program. The Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study recruits 800 patients over a 4-yr period and follows them for a minimum of 2 yr and maximum of 6 yr. Patients are 10-17 yr of age, within 2 yr of diagnosis of diabetes at the time of randomization, lack evidence of autoimmunity, and have sustained C-peptide secretion. The primary outcome is time to loss of glycemic control, defined as a hemoglobin A1c >8% for 6 consecutive months. Secondary outcomes include the effect of the alternative treatments on insulin secretion and resistance, body composition, nutrition, physical activity and fitness, cardiovascular risk monitoring, microvascular complications, quality of life, depression, eating pathology, and resource utilization. TODAY is the first large-scale, systematic study of treatment effectiveness for T2DM in youth. When successfully completed, this study will provide critical new information regarding the natural history of T2DM in youth, the benefits of initiating early aggressive treatment in these patients, and the efficacy of delivering an intensive and sustained lifestyle intervention to children with T2DM.

Economic evaluation of angiotensin receptor blockers in type 2 diabetes, hypertension, and nephropathy

There is a rising incidence and prevalence of ESRD as a result of diabetes, with poor outcome and growing costs. Recently, two large trials, the Irbesartan Diabetic Nephropathy Trial (IDNT) and Reduction of Endpoints in NIDDM with the Angiotensin II Antagonist Losartan (RENAAL), showed that angiotensin receptor blockers (ARB) are more effective than traditional antihypertensive therapies at reducing progression toward ESRD in hypertensive patients with type 2 diabetes and overt nephropathy, regardless of changes in BP. The results of these two trials were used to compare the costs of ARB with those of renal replacement therapy (dialysis and renal transplantation) in an effort to establish whether ARB are cost-saving because they delay ESRD. Two different pharmacoeconomic approaches were used. With regard to the RENAAL trial, the number of ESRD days on losartan therapy as compared with the number of ESRD days on standard antihypertensive therapy was calculated, and the difference between the two was combined with the costs of ESRD. In the IDNT trial, Markov models were applied to assess the economic impact of irbesartan and to extrapolate future clinical and cost outcomes. Several economic analyses were performed in the United States and in European countries. Applying pharmacoeconomic models showed that treatment with ARB was associated with a greater improvement in life expectancy and lower total costs compared with amlodipine and standard antihypertensive therapy. Therefore, treating patients with type 2 diabetes, nephropathy, and hypertension with ARB is life- and cost-saving compared with traditional antihypertensive therapy.

Is the number of documented diabetes process-of-care indicators associated with cardiometabolic risk factor levels, patient satisfaction, or self-rated quality of diabetes care? The Translating Research into Action for Diabetes (TRIAD) study

OBJECTIVE

Simple process-of-care indicators are commonly recommended to assess and compare quality of diabetes care across health plans. We sought to determine whether variation in the number of simple diabetes processes of care across provider groups is associated with variation in other quality indicators, including cardiometabolic risk factor levels, patient satisfaction with care, or patient-rated quality of care.

RESEARCH DESIGN AND METHODS

We used cross-sectional survey and chart audit data for 8,733 patients with diabetes who received care from 68 provider groups nested in 10 health plans that participated in the Translating Research Into Action for Diabetes study. Analyses using hierarchical regression models assessed associations of the mean number of seven simple process measures with each of the following: HbA(1c) (A1C), systolic blood pressure (SBP), HDL and LDL cholesterol levels, patient satisfaction with care, and patient-rated quality of care.

RESULTS

After adjusting for case-mix differences across groups and plans, an average of one additional documented process of care for each patient in a group or plan was associated with significantly lower mean LDL cholesterol levels (-4.51 mg/dl [95% CI 1.46-7.58]) but not with A1C, SBP, or HDL cholesterol levels. The number of care processes documented was associated with patient satisfaction measures and self-rated quality of diabetes care.

CONCLUSIONS

Variation in the number of simple process-of-care indicators across provider groups or health plans is associated with differences in patient-centered measures of quality, but assessment of the quality of cardiometabolic risk factor control will require more advanced clinical performance indicators.

Improving Antihypertensive Therapy in Patients with Diabetic Nephropathy

Nearly all patients with diabetic nephropathy have comorbid hypertension, which greatly elevates the risk for cardiovascular events. As patients are surviving longer, their risk of progressing to end-stage renal disease is increasing, particularly in patients with type 2 diabetes. Prevention of cardiovascular and renal events in this population requires diligent efforts to control blood pressure, serum glucose, and serum lipids. Improving antihypertensive therapy in patients with diabetic nephropathy relies on the following unified strategies: reducing blood pressure to <130/80 mm Hg, prescribing an agent that blocks the renin-angiotensin system, and designing an antihypertensive regimen that both reduces albuminuria and provides cardiovascular protection. A majority of patients will require three or more antihypertensive agents to achieve these objectives. Appropriate antihypertensive therapy in patients with diabetic nephropathy delays progression of renal disease and leads to substantial cost savings.

Sustainable and tenable renal health model: A Latin American proposal of classification, programming, and evaluation

BACKGROUND

End-stage renal disease (ESRD) presents a major problem to public health, with complex implications for social and economic structures in every nation of the world. Clearly, Latin American and Caribbean countries are not able to meet the needs of every patient requiring dialysis treatment at ESRD. Consequently, a considerable number of patients die every year as a result of lack of resources. Aware of this serious social, ethical, and economic problem, the Latin American Society of Nephrology and Hypertension proposed a new renal health concept in the region. In December 2002, at the workshop in Valdivia, Chile, a modification to the National Kidney Foundation Classification of Chronic Kidney Disease was approved.

PROJECT

According to modifications to the concept of chronic kidney disease approved in the Declaration of Valdivia, a new Renal Health Model was proposed. It consists of including orderly follow-up in patients' charts, starting from the earliest stage, and a model establishing a guideline for the reallocation of financial resources to guarantee continuity of treatment to patients with ESRD.

CONCLUSION

The implementation of the Renal Health Program in health ministries of Latin American and Caribbean countries would allow for a substantial improvement in renal health prevention and management, as a result of better distribution of financial and human resources.

Cost-effectiveness of irbesartan in diabetic nephropathy: a systematic review of published studies

BACKGROUND

To review published studies on the cost-effectiveness of the use of irbesartan for treatment of advance overt nephropathy in patients with type 2 diabetes and hypertension.

METHODS

Articles were identified based on a search of the PubMed databases using the keywords 'irbesartan', 'ESRD', 'cost-effectiveness', 'nephropathy' and 'costs', and by personal communication with the authors. Only studies published in the last 10 years were included. All costs data from the cost-effectiveness studies were inflated to 2003 Euros using published governmental conversion tables.

RESULTS

Seven published studies were identified, spanning the following country settings: the US, Belgium and France, Germany, Hungary, Italy, Spain, and the UK. In each, the same pharmacoeconomic model was adapted using country-specific data to project and evaluate the clinical and cost outcomes of the treatment arms of the Irbesartan in Diabetic Nephropathy Trial (IDNT) (irbesartan, amlodipine or standard blood pressure control). Mean time to onset of ESRD was 8.23 years for irbesartan, 6.82 years for amlodipine and 6.88 years for the control (values were the same for Belgium, France, Germany, Hungary, Italy and Spain as transition probabilities for progression to ESRD were all derived from the IDNT). Mean cumulative incidence of ESRD was 36% with irbesartan, 49% with amlodipine and 45% with control treatment. Treatment with irbesartan was projected to improve life expectancy compared to both amlodipine and control in all seven published studies. Analysis of total lifetime costs showed that irbesartan treatment was cost saving compared to the other two treatment regimens, due to the associated reduction in ESRD cases. Cost savings with irbesartan became evident very early; after 2-3 years of treatment in most settings.

CONCLUSIONS

Modelling studies based on the IDNT published to date suggest that irbesartan treatment in patients with type 2 diabetes, hypertension and advanced nephropathy is both life- and cost-saving compared to amlodipine or control.

The cost-effectiveness of lifestyle modification or metformin in preventing type 2 diabetes in adults with impaired glucose tolerance

BACKGROUND

The Diabetes Prevention Program (DPP) demonstrated that interventions can delay or prevent the development of type 2 diabetes.

OBJECTIVE

To estimate the lifetime cost-utility of the DPP interventions.

DESIGN

Markov simulation model to estimate progression of disease, costs, and quality of life.

DATA SOURCES

The DPP and published reports.

TARGET POPULATION

Members of the DPP cohort 25 years of age or older with impaired glucose tolerance.

TIME HORIZON

Lifetime.

PERSPECTIVES

Health system and societal.

INTERVENTIONS

Intensive lifestyle, metformin, and placebo interventions as implemented in the DPP.

OUTCOME MEASURES

Cumulative incidence of diabetes, microvascular and neuropathic complications, cardiovascular complications, survival, direct medical and direct nonmedical costs, quality-adjusted life-years (QALYs), and cost per QALY.

RESULTS OF BASE-CASE ANALYSIS

Compared with the placebo intervention, the lifestyle and metformin interventions were estimated to delay the development of type 2 diabetes by 11 and 3 years, respectively, and to reduce the absolute incidence of diabetes by 20% and 8%, respectively. The cumulative incidence of microvascular, neuropathic, and cardiovascular complications were reduced and survival was improved by 0.5 and 0.2 years. Compared with the placebo intervention, the cost per QALY was approximately 1100 dollars for the lifestyle intervention and $31 300 for the metformin intervention. From a societal perspective, the interventions cost approximately 8800 dollars and 29,900 dollars per QALY, respectively. From both perspectives, the lifestyle intervention dominated the metformin intervention.

RESULTS OF SENSITIVITY ANALYSIS

Cost-effectiveness improved when the interventions were implemented as they might be in routine clinical practice. The lifestyle intervention was cost-effective in all age groups. The metformin intervention did not represent good use of resources for persons older than 65 years of age.

LIMITATIONS

Simulation results depend on the accuracy of the underlying assumptions, including participant adherence.

CONCLUSIONS

Health policy should promote diabetes prevention in high-risk individuals.

Cost-effectiveness of early irbesartan treatment versus control (standard antihypertensive medications excluding ACE inhibitors, other angiotensin-2 receptor antagonists, and dihydropyridine calcium channel blockers) or late irbesartan treatment in patients with type 2 diabetes, hypertension, and renal disease

OBJECTIVE

The aim of this study was to determine the most cost-effective time point for initiation of irbesartan treatment in hypertensive patients with type 2 diabetes and renal disease.

RESEARCH DESIGN AND METHODS

This study was a Markov model-simulated progression from microalbuminuria to overt nephropathy, doubling of serum creatinine, end-stage renal disease, and death in hypertensive patients with type 2 diabetes. Two irbesartan strategies were created: early irbesartan 300 mg daily (initiated with microalbuminuria) and late irbesartan (initiated with overt nephropathy). These strategies were compared with control, which consisted of antihypertensive therapy with standard medications (excluding ACE inhibitors, other angiotensin-2 receptor antagonists, and dihydropyridine calcium channel blockers) with comparable blood pressure control, initiated at microalbuminuria. Transition probabilities were taken from the Irbesartan in Reduction of Microalbuminuria-2 study, Irbesartan in Diabetic Nephropathy Trial, and other published sources. Costs and life expectancy, discounted at 3% yearly, were projected over 25 years for 1,000 simulated patients using a third-party payer perspective in a U.S. setting.

RESULTS

Compared with control, early and late irbesartan treatment in 1,000 patients were projected to save (mean +/- SD) 11.9 +/- 3.3 million dollars and 3.3 +/- 2.7 million dollars, respectively. Early use of irbesartan added 1,550 +/- 270 undiscounted life-years (discounted 960 +/- 180), whereas late irbesartan added 71 +/- 40 life-years (discounted 48 +/- 27) in 1,000 patients. Early irbesartan treatment was superior under a wide-range of plausible assumptions.

CONCLUSIONS

Early irbesartan treatment was projected to improve life expectancy and reduce costs in hypertensive patients with type 2 diabetes and microalbuminuria. Later use of irbesartan in overt nephropathy is also superior to standard care, but irbesartan should be started earlier and continued long term.

Blood pressure control and nephroprotection in diabetes

Achievement of recommended levels of blood pressure as prescribed by guidelines (i.e., systolic blood pressure of < 130 mmHg in people with nephropathy secondary to type 2 diabetes) generally requires three or more different antihypertensive agents that have complementary modes of action. This systolic goal blood pressure, recommended by generally all international guideline committees, was derived from largely observational studies demonstrating a greater reduction of cardiovascular risk and preservation of kidney function at these levels. Commonly used antihypertensive combinations include angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers, which have compelling indications for use in people with kidney disease and/or diabetes, combined with a diuretic, generally a thiazide-type agent. If additional therapy is required, either a beta-blocker or a calcium antagonist may be added to this antihypertensive "cocktail." Beta-blockers are particularly effective in people with a high sympathetic drive (i.e., high pulse rates) to lower blood pressure and reduce cardiovascular risk. Moreover, in recent studies, their benefits on kidney function, both by reducing macroalbuminuria and slowing the decline of kidney function, make them good agents to add in the appropriate clinical setting. With all these potential benefits of achieving blood pressure goals, it is unfortunate that only 11% of people being treated for hypertension with diabetic kidney disease achieve the blood pressure goal of < 130 mmHg, likely contributing to the climbing incidence of people starting dialysis. Physicians need to work harder and educate patients on the importance of achieving these lower blood pressure guidelines.

Are low-income elderly patients at risk for poor diabetes care?

OBJECTIVE

Diabetes is common among low-income elderly, dual-eligible (DE) Medicare/Medicaid patients resulting in significant morbidity, mortality, and cost. However, the quality of diabetes care delivered to these patients has not been evaluated. The aims of this study were to describe the quality of diabetes care provided to DE patients and compare it with non-DE patients.

RESEARCH DESIGN AND METHODS

This was a cross-sectional analysis of administrative claims from 1 January 1997 through 31 December 1998. A total of 9,453 patients aged 65-75 years with diabetes participated in the study. These were Colorado Medicare fee-for-service (FFS) outpatients. The main outcome measures consisted of a proportion of patients receiving an annual hemoglobin A1c test, biennial eye examination, biennial lipid test, and all three of these care processes.

RESULTS

The mean patient age was 71 +/- 2.8 years. Over 22% of patients were identified as dual eligible, and they were significantly more likely to be younger, female, and of minority race/ethnicity; reside in a rural location; and have comorbid conditions compared with the non-DE population. DE patients had more visits to primary care physicians, emergency departments, and hospitalizations but were less likely to visit endocrinologists. DE patients were significantly less likely to receive an annual A1c test (73 vs. 81%; P < 0.0001), biennial ophthalmologic examination (63 vs. 75%; P < 0.0001), and biennial lipid testing (43 vs. 57%; P < 0.0001). The adjusted odds ratio of urban DE patients receiving all three care measures was 0.60 (95% CI 0.52-0.69) compared with urban non-DE patients. Minority race/ethnicity and emergency department use were significantly associated with not receiving diabetes care, whereas endocrinology visits were associated with an increased odds of receiving diabetes care.

CONCLUSIONS

DE Medicare/Medicaid status was independently associated with not receiving diabetes care, especially among those in urban areas.

Incorporating patient-centered outcomes in the analysis of cost-effectiveness: imaging strategies for renovascular hypertension

OBJECTIVE

Our aim was to assess the contribution of patient-centered short-term disutilities and quality-of-life measures in the cost-effectiveness analysis of CT angiography, MR angiography, and conventional angiography in patients with medication-resistant hypertension.

MATERIALS AND METHODS

A decision analytic model compared the life expectancy and incremental cost per life year using three initial diagnostic tests in a cohort of hypothetical individuals with medication-resistant hypertension over a range of renal artery stenosis probabilities: CT angiography (sensitivity, 96%; specificity, 96%; cost, $865); MR angiography (98%, 94%, $850); and conventional angiography (99%, 99%, $2,627). All imaging strategies were compared with a base case scenario mimicking the natural history of medication-resistant hypertension and with a scenario immediate enhanced medical therapy without prior imaging. Individuals without evidence of renal artery stenosis on initial testing underwent conventional angiography if enhanced medical therapy failed to control hypertension. Individuals diagnosed with renal artery stenosis on MR angiography required conventional angiography for definitive stent treatment ($11,1223). Blood pressure response to renal artery stenting or enhanced medical therapy varied according to blood pressure, as did the incidence of myocardial infarction and stroke resulting from hypertension. Patients who progressed to end-stage renal disease received dialysis ($60,000 per year). Quality-of-life adjustments were made for patients with hypertension, end-stage renal disease, myocardial infarction, and stroke. Short-term disutilities from undergoing an imaging test were included. The analysis accounted for direct costs derived from Medicare reimbursements and total costs derived from the literature.

RESULTS

All imaging strategies were cost-effective compared with enhanced medical therapy alone or with natural history. When only direct costs were considered, MR angiography was the preferred strategy, with conventional angiography as a cost-effective alternative to MR angiography. When total costs were considered, conventional angiography dominated all other strategies. Adjusting for quality of life decreased the incremental cost-effectiveness ratios, making an already competitive strategy a more favorable alternative to the base case. Adjusting for test-related disutility did not significantly influence the cost-effectiveness of any of the imaging tests. Despite marked variation in the key clinical and cost variables, MR angiography remained the most cost-effective strategy.

CONCLUSION

In the evaluation and treatment of medication-resistant hypertension, strategies that included preliminary imaging saved more lives than did the immediate institution of enhanced medical therapy at a lesser cost.

Cost-effective strategies in the prevention of diabetic nephropathy

A significant subgroup of patients with diabetes mellitus are predisposed to developing diabetic nephropathy and it is in this subgroup that other diabetes- related complications, and in particular greatly increased cardiovascular disease risk, are concentrated. The high personal, social and financial costs of managing end-stage renal failure and the other complications associated with diabetic nephropathy make a powerful case for screening and effective intervention programmes to prevent the condition or retard its progression. As major breakthroughs in finding genetic susceptibility factors remain elusive, screening efforts continue to be based on microalbuminuria testing, despite increasing recognition of its limitations as a positive predictor of nephropathy. Interventions have been extensively studied, but results remain conflicting. Economic evaluations of such screening and intervention programmes are essential for health planners, yet models of the cost/benefit ratio of such interventions often rely on a rather slim evidence base. Where economic models are developed, they are frequently based on those papers that propound the greatest clinical benefits of a given intervention, leading to a possible over-estimation of the advantages of the chosen approach. Furthermore, the benefits of even such generally accepted interventions as ACE inhibitor treatment are less firmly established than generally appreciated. Lifestyle interventions are instinctively attractive, but are by no means a low-cost option (as is often assumed by both medical professionals and politicians). This review critically assesses the evidence for clinical efficacy and economic benefit of microalbuminuria screening and interventions such as intensive glycaemic control, antihypertensive treatment, ACE inhibition and angiotensin receptor blockade, dietary protein restriction and lipid-modifying therapy. The various costs associated with diabetic nephropathy are so great that even expensive interventions may have a favourable cost/benefit ratio, provided they are truly effective.

The health care costs of diabetic nephropathy in the United States and the United Kingdom

PROBLEM

Diabetic nephropathy (DN) is a common microvascular complication of diabetes and can result in end-stage renal disease (ESRD) necessitating long-term dialysis or kidney transplantation. The costs of these complications are relatively high. The aim of this study was to quantify and compare the rates and annual costs of DN in the USA and the UK.

METHODS

A cost of illness model was used to estimate the numbers of people with DN (microalbuminuria, overt nephropathy, and ESRD) or a previous kidney transplant at a given point in time and the numbers of new kidney transplants during a year. All costs were estimated in 2001 currencies. A sensitivity analysis assessed the robustness of the national annual cost estimates.

RESULTS

In the USA, the total annual medical costs incurred by all payers in managing DN were US dollars 1.9 billion for Type 1 diabetes (range: US dollars 1.0-2.8 billion), US dollars 15.0 billion for Type 2 diabetes (range: US dollars 7.6-22.4 billion), and US dollars 16.8 billion for all diabetes (range: US dollars 8.5-25.2 billion). In the UK, the total annual costs to the National Health Service (NHS) of managing DN were US dollars 231 million ( pound 152 million) for Type 1 diabetes (range: US dollars 190-350 million [ pound 125-230 million]), US dollars 933 million (pound 614 million) for Type 2 diabetes (range: US dollars 809 million-US dollars 1.4 billion [pound 532-927 million]), and US dollars 1.2 billion ( pound 765 million) for all diabetes (range: US dollars 999 million-US dollars 1.8 billion [pound 657 million- pound 1.2 billion]).

CONCLUSIONS

The total annual cost of DN is 13 times greater in the USA than in the UK. Controlling for the substantially higher number of people at risk, the total cost per person with DN and/or a kidney transplant is 40% higher: US dollars 3735 in the USA and US dollars 2672 (pound 1758) in the UK.

Improving diabetes processes of care in managed care

OBJECTIVE

To evaluate the impact of systematic patient evaluation and patient and provider feedback on the processes and intermediate outcomes of diabetes care in Independent Practice Association model internal medicine practices.

RESEARCH DESIGN AND METHODS

Nine practices providing care to managed care patients were randomly assigned as intervention or comparison sites. Intervention-site subjects had Annual Diabetes Assessment Program (ADAP) assessments (HbA(1c), blood pressure, lipids, smoking, retinal photos, urine microalbumin, and foot examination) at years 1 and 2. Comparison-site subjects had ADAP assessments at year 2. At Intervention sites, year 1 ADAP results were reviewed with subjects, mailed to providers, and incorporated into electronic medical records with guideline-generated suggestions for treatment and follow-up. Medical records were evaluated for both groups for the year before both the year 1 and year 2 ADAP assessments. Processes and intermediate outcomes were compared using linear and logistic mixed hierarchical models.

RESULTS

Of 284 eligible subjects, 103 of 173 (60%) at the Intervention sites and 71 of 111 (64%) at the comparison sites participated; 83 of 103 (81%) of the intervention-site subjects returned for follow-up at year 2. Performance of the six recommended assessments improved in intervention-site subjects at year 2 compared with year 1 (5.8 vs. 4.3, P = 0.0001) and compared with comparison-site subjects at year 2 (4.2, P = 0.014). No significant changes were noted in intermediate outcomes.

CONCLUSIONS

The ADAP significantly improved processes of care but not intermediate outcomes. Additional interventions are needed to improve intermediate outcomes.

The cost-effectiveness of irbesartan in the treatment of hypertensive patients with type 2 diabetic nephropathy

BACKGROUND

End-stage renal disease (ESRD)-related health care costs are substantial. Improving clinical outcomes in patients at risk of progression to ESRD could lead to considerable health care savings.

OBJECTIVE

We estimated the cost-effectiveness of irbesartan compared with placebo or amlodipine in the treatment of patients with type 2 diabetes mellitus, hypertension, and overt nephropathy.

METHODS

Three treatments for hypertension patients with type 2 diabetes mellitus and nephropathy were assessed: (1) irbesartan, (2) amlodipine, and (3) placebo. A Markov model was developed based on primary data from the Irbesartan in Diabetic Nephropathy Trial and the United States Renal Data System. Projected survival and costs were compared for each treatment at 3-, 10-, and 25-year time horizons. Different assumptions of treatment benefits and costs were tested with use of sensitivity analyses.

RESULTS

At 10 and 25 years, the model projected irbesartan to be both the least costly and most effective (ie, demonstrating a survival advantage) strategy. At 25

Identification and management of diabetic nephropathy in the diabetes clinic

OBJECTIVE

To examine the prevalence and management of diabetic nephropathy in a diabetes clinic.

RESEARCH DESIGN AND METHODS

Characteristics of nephropaths identified by existing screening practice (phase I, albuminuria >20 mg/l in three separate urine samples), were compared with those identified by a nurse-led management program (phase II, in which screening for nephropathy was based on albumin-to-creatinine ratio in a single random urine specimen).

RESULTS

In phase I, 644 patients attended a diabetes clinic over a 6-month period. Microalbuminuria results were available for 485 patients (75%). A total of 115 patients were identified as nephropaths (prevalence 17.8%). Of these patients, 91% had type 2 diabetes. During phase II, prospective analysis of urinary albumin-to-creatinine ratio was carried out in 880 patients over 8 months. A total of 174 patients were identified as nephropaths (prevalence 20%). Of these, 134 patients had been identified by existing screening protocols. Forty had no previous record of microalbuminuria and were therefore newly identified by prospective screening. Systolic blood pressure guidelines were met in only 31% of all known nephropaths and 26.5% of newly diagnosed nephropaths. Diastolic blood pressure guidelines were met in 36% of all known and 38% of newly diagnosed nephropaths. In the patient group of known nephropaths from phases I and II, 62% were prescribed ACE inhibitors (ACEIs) or angiotensin II receptor (AIIR) antagonists. In the newly identified nephropathy patient cohort from phase II, 48% used ACEIs or AIIR antagonists.

CONCLUSIONS

Introduction of a nurse-led management program significantly improved detection of nephropathy. We are currently evaluating its impact on clinical management.

Outcome studies in diabetic nephropathy

Outcome studies in diabetic nephropathy have focused on strategies to prevent progression of diabetic nephropathy, the leading cause of ESRD in the United States. Once diabetics develop overt nephropathy, prognosis is poor. Risk factors for diabetic nephropathy are discussed, and include hyperglycemia, hypertension, angiotensin II, proteinuria, dyslipidemia, smoking, and anemia. Major outcomes as well as outcome studies in diabetic nephropathy for patients with microalbuminuria and macroalbuminuria are reviewed. Furthermore, the role of therapy with angiotensin converting enzyme inhibitors, angiotensin II receptor blockers, calcium channel blockers, and mineralocorticoid receptor antagonists as well as selected combination therapy are discussed. Recommendations for therapy with ace inhibitors and angiotensin II receptor blockers are made based on this evidence.

Losartan reduces the costs associated with diabetic end-stage renal disease: the RENAAL study economic evaluation

OBJECTIVE

To evaluate the within-trial effect of losartan and conventional antihypertensive therapy (CT) compared with placebo and CT on the economic cost associated with end-stage renal disease (ESRD).

RESEARCH DESIGN AND METHODS

The Reduction of End Points in Type 2 Diabetes With the Angiotensin II Antagonist Losartan (RENAAL) study was a multinational double-blind randomized placebo-controlled clinical trial designed to evaluate the renal protective effects of losartan on a background of CT (excluding ACE inhibitors and angiotensin II receptor agonists [AIIAs]) in patients with type 2 diabetes and nephropathy. The primary composite end point was doubling of serum creatinine, ESRD, or death. Data on the duration of ESRD were used to estimate the economic benefits of slowing the progression of nephropathy. The cost associated with ESRD was estimated by combining the days each patient experienced ESRD with the cost of ESRD over time. The cost of ESRD for individuals with diabetes was estimated using data from the U.S. Renal Data System. Total cost was estimated as the sum of the cost associated with ESRD and the cost of study therapy. RESULTS-We estimated that losartan and CT compared with placebo and CT reduced the number of days with ESRD by 33.6 per patient over 3.5 years (P = 0.004, 95% CI 10.9-56.3). This reduction in ESRD days resulted in a decrease in cost associated with ESRD of 5144 US dollars per patient (P = 0.003, 95% CI 1701 to 8587 US dollars). After accounting for the cost of losartan, the reduction in ESRD days resulted in a net savings of 3522 US dollars per patient over 3.5 years (P = 0.041, 143 to 6900 US dollars).

CONCLUSIONS

Treatment with losartan in patients with type 2 diabetes and nephropathy not only reduced the incidence of ESRD, but also resulted in substantial cost savings.

The economics of screening and treatment in type 2 diabetes mellitus

A systematic review of the literature was conducted to identify articles on the economics of type 2 diabetes mellitus. Articles were classified into two main categories: cost/burden-of-illness studies of type 2 diabetes and economic evaluations of type 2 diabetes interventions. This systematic review was supplemented by an overview of the findings relating to economic evaluations of associated diabetic complications. A number of conclusions emerge from this review, the most important of which is that intensive treatment of patients with type 2 diabetes appears to be relatively cost effective compared with more conservative strategies. This finding reflects the cost offsets that arise from the range and degree of complications attributable to diabetes. Primary prevention of type 2 diabetes also appears to be cost effective, particularly in high-risk groups. The evidence on screening for type 2 diabetes is less conclusive and further economic analysis is required.

Do HEDIS measures reflect cost-effective practices?

PURPOSE

Whether the Health Plan Employer Data and Information Set (HEDIS) performance measures for managed care plans encourage a cost-effective use of society's resources has not been quantified. Our study objectives were to examine the cost-effectiveness evidence for the clinical practices underlying HEDIS 2000 measures and to develop a list of practices not reflected in HEDIS that have evidence of cost effectiveness.

DATA SOURCES

Two databases of economic evaluations (Harvard School of Public Health Cost-Utility Registry and the Health Economics Evaluation Database) and two published lists of cost-effectiveness ratios in health and medicine.

STUDY SELECTION

For each of the 15 "effectiveness of care" measures in HEDIS 2000, we searched the data through 1998 for cost-effectiveness ratios of similar interventions and target populations. We also searched for important interventions with evidence of cost-effectiveness (<$20,000 per life-year [LY] or quality-adjusted life year [QALY] gained), which are not included in HEDIS. All ratios were standardized to 1998 dollars. The data were collected and analyzed during fall 2000 to summer 2001.

DATA EXTRACTION

Cost-effectiveness ratios reporting outcomes in terms of cost/LY or cost/QALY gained were included if they matched the intervention and population covered by the HEDIS measure.

DATA SYNTHESIS

Evidence was available for 11 of the 15 HEDIS measures. Cost-effectiveness ranges from cost saving to $660,000/LY gained. There are numerous non-HEDIS interventions with some evidence of cost effectiveness, particularly interventions to promote healthy behaviors.

CONCLUSIONS

HEDIS measures generally reflect cost-effective practices; however, in a number of cases, practices may not be cost effective for certain subgroups. Data quality and availability as well as study perspective remain key challenges in judging cost effectiveness. Opportunities exist to refine existing measures and to develop additional measures, which may promote a more efficient use of societal resources, although more research is needed on whether these measures would also satisfy other desirable attributes of HEDIS.

Slowing the progression of chronic renal failure: economic benefits and patients' perspectives

Because of the predicted increase in end-stage renal disease (ESRD) incidence (projected increase from 1998 to 2010; 86,825 to 172,667), prevalence (projected increase from 1998 to 2010; 326,217 to 661,330), and cost (total cost based on 1998 ratio of Medicare versus non-Medicare cost; $16.74 billion in 1998 to $39.35 billion in 2010), a cohesive national effort is needed to develop strategies to slow the progression of chronic renal failure (CRF). The question arises to how much reduction in the progression of CRF would lead to a meaningful decrease in the prevalence and cost of ESRD. There are no objective data that show the economic impact of slowing the progression of CRF. We developed a mathematical model to assess the economic impact of decreasing the progression of CRF by 10%, 20%, and 30%. US Renal Data System (USRDS) projections were used to model the rate of increase in ESRD incidence and prevalence. Glomerular filtration rate (GFR) at the initiation of ESRD therapy and cost per patient-year were based on USRDS data. The average decline in GFR in subjects with CRF was estimated to be 7.56 mL/min/y. All dollar savings reflect 1998 costs, discounted for the future at 3% per annum. We also determined how much slowing of the progression of CRF is important from patients' perspectives by means of a written questionnaire (which inquired about willingness to go on a restricted diet, take six extra medications per day, and make six extra office visits per year) and calculation of the pre-ESRD time gained for different degrees of reduction in the progression of CRF. If the rate of decline in GFR decreased by 10%, 20%, and 30% after December 31, 1999, in all patients with GFRs of 60 mL/min or less, cumulative direct healthcare savings through 2010 would equal approximately $18.56, $39.02, and $60.61 billion, respectively. For a 10%, 20%, and 30% decrease in the rate of decline in GFR in all patients with a GFR of 30 mL/min or less, estimated cumulative savings through 2010 equal $9.06, $19.98, and $33.37 billion, respectively. Responses to the questionnaire showed that approximately 79% of subjects with CRF (n = 113) perceived a few weeks' dialysis-free period significant (P < or = 0.0001), a period corresponding to a 10% reduction in the rate of decline in GFR. Our data suggest that the cumulative economic impact of slowing the progression of CRF, even by as little as 10%, would be staggering. They provide strong support for the development and implementation of intensive reno-protective efforts beginning at the early stages of chronic renal disease and continued throughout its course.

Role of ACE inhibitors in patients with diabetes mellitus

The adjective 'epidemic' is now attributed to the rapidly growing number of patients with diabetes mellitus, mainly type 2. and the specific complications linked to this disorder. Provided they are recognised early enough, these different complications can be treated; in some patients the evolutive course of these complications can be slowed or even stopped. Furthermore, some recent observations suggest that specific tissular lesions may be prevented or even reversed. Although glycaemic control is essential, other therapeutic measures that must also be taken include those to control blood pressure and to lower lipid levels. Of the agents available to control the complications of diabetes mellitus, cardiovascular drugs, and particularly ACE inhibitors, have a pre-eminent place. Experimental and epidemiological data suggest that activation of the renin-angiotensin-aldosterone system plays an important role in increasing in the micro- and macrovascular complications in patients with diabetes mellitus. Not only are ACE inhibitors potent antihypertensive agents but there is a growing body of data indicating that also they have a specific 'organ-protective' effect. For the same degree of blood pressure control, compared with other antihypertensive agents, ACE inhibitors demonstrate function and tissue protection of considered organs. ACE inhibitors have been reported to improve kidney, heart, and to a lesser extent, eye and peripheral nerve function of patients with diabetes mellitus. These favourable effects are the result of inhibition of both haemodynamic and tissular effects of angiotensin II. Finally, there are a growing number of arguments favouring the use of ACE inhibitors very early in patients with diabetes mellitus.

Antihypertensive treatment with and without benazepril in patients with chronic renal insufficiency: a US economic evaluation

OBJECTIVE

To conduct an economic analysis in the US of antihypertensive treatment with and without benazepril in patients with chronic renal insufficiency.

DESIGN

A four-state Markov model, using clinical data obtained from a 3-year randomised clinical trial [the Angiotensin-Converting-Enzyme Inhibition in Progressive Renal Insufficiency (AIPRI) study] plus its extension study (median 3.6 years), and cost data obtained from published US sources. The period of analysis was 7 years following randomisation.

PERSPECTIVE

Healthcare payer.

SETTING

Clinical data were obtained from multiple medical centres in three European countries as described in the published studies. Key economic data were obtained from the US Healthcare Financing Administration's End Stage Renal Disease programme.

PATIENTS AND INTERVENTIONS

In the clinical studies on which this economic analysis was based, patients with chronic renal insufficiency of various aetiologies were randomised to antihypertensive therapy with or without concomitant benazepril.

MAIN OUTCOME MEASURES AND RESULTS

Over 7 years of analysis, patients randomised to antihypertensive treatment with concomitant benazepril therapy incurred on average USD12991 (1999 values) lower medical costs than patients prescribed antihypertensive treatment without benazepril, and obtained an additional 0.091 quality-adjusted life years (QALYs). Costs and QALYs were greater for the benazepril arm than the placebo arm for all years of analysis after the first. Rank order stability of results favouring the benazepril therapy arm was found in sensitivity analyses of changes in key model parameters. Additional economic and health benefits favouring patients receiving benazepril would be seen if underlying model rates of dialysis and transplantation were increased, as may be appropriate to reflect treatment practice differences in the US relative to European countries.

CONCLUSIONS

Benazepril therapy as a component of antihypertensive treatment of persons with chronic renal insufficiency initially costs money, but investment costs are recouped quickly and return on investment continues to grow. The impact of end-stage renal disease on patient health and healthcare costs is great. Thus, the quality-adjusted survival benefits and overall cost savings seen in benazepril recipients over a prolonged period (2 to 7 years) indicate that the strategy of prescribing benazepril to reduce progression of renal disease in patients with renal insufficiency is both clinically and economically beneficial compared with current antihypertensive regimens without ACE inhibition.

The role of cost-effectiveness analysis and health insurance in diabetes care

The theme of World Diabetes Day for 1999 is 'The Costs of Diabetes'. This theme was chosen quite purposely to reflect the broad nature in which diabetes affects individuals, families, and society. For the theme can highlight the importance of diabetes from a medical, social, or economic perspective. This presentation addresses two issues, cost-effectiveness analysis and financial barriers to care, that pertain to the economic viewpoint. Economically, the costs of diabetes are varied. They include items that one can easily recognize, such as the expenditures related to medical treatment for diabetes (direct costs) or the earnings lost to individuals prematurely disabled or dying young (indirect costs). Other less well known costs exists as well. These include the opportunity costs to individuals with diabetes who forego other 'opportunities in life' because they made a decision to devote their financial or time resources to diabetes care. They also include costs to society, such as the impact of using existing resources in diabetes care unwisely, or having inappropriate priorities. Cost-effectiveness analyses in diabetes care address this last point. Health insurance issues highlight one aspect of opportunity costs in diabetes care.

The impact of diabetes on economic costs in dialysis patients: experiences in Taiwan

Diabetes mellitus carries a great burden on healthcare costs due to its growing population and high co-morbidity. This adverse effect sustains even when patients develop end-stage renal disease (ESRD). We here present data showing the effect of diabetes on economic costs in dialysis therapy in Taiwan. As of the end of 1997, we have 22,027 ESRD patients with a prevalence and incidence rate of 1013 and 253 per million populations, respectively. Diabetic nephropathy is the second most common cause of the underlying renal diseases, but accounts for 24.8% of the prevalent patients and 35.9% of the incident cases. The diabetic patients engendered 11.8% more expense for care of dialysis than the non-diabetic patients (US $26,988 vs. US $24,146 per patient-year). Higher inpatient cost mainly account for the difference. As compared to non-diabetic patients, the diabetic patients had 3.5 times more inpatients costs (US $1325 vs. US $4677 per patient-year), and higher proportion of inpatient-to-annualized cost ratio (5.5 vs. 17.3%) resulting from their more frequent hospitalization (0.59 vs. 1.13 times per patient-year) and longer hospital stay (6.7 vs. 18.9 days per patient-year). The major causes responsible for a more frequent hospitalization were cardiovascular disease, poorly controlled hyperglycemia, sepsis and failure of vascular access. The annualized costs for care of dialysis patients in Taiwan, including inpatient and outpatient costs, averaged US $25,576 per patient-year. This value is approximately half of that in most of the western countries and Japan. Thus, a more cost-effective way to achieve savings is to reduce the high incidence rate of dialysis population and to maximize the quality of dialysis treatment for avoiding hospitalization. Recent studies had shown that tight blood pressure control, intensive glycemic control, and use of angiotensin converting enzyme inhibitors in diabetic patients significantly reduced not only the rate of progressive renal failure, but also substantially reduced the cost of complications and led to higher cost effectiveness. Once diabetic patients reach stage of ESRD, an optimized pre-ESRD care and consideration of kidney transplantation are essential in terms of better patient survival and cost savings.

A clinical trial in type 2 diabetic nephropathy

A prospective, randomized, three-armed, double-blind, placebo-controlled clinical trial has been completed in 210 sites worldwide to determine whether the angiotensin II receptor blocker irbesartan or the calcium channel blocker amlodipine has a renoprotective effect in patients with overt type 2 diabetic nephropathy. A total of 1,715 subjects randomized during a 3-year period were followed a minimum of 2 years. The goal for all treatment groups was to achieve equivalent blood pressure control, with the blinded study drug (irbesartan, amlodipine, or placebo) as primary therapy with additional antihypertensive drugs, excluding angiotensin-converting enzyme inhibitors, calcium antagonists, and angiotensin II receptor antagonists, to achieve seated systolic blood pressure less than 135 mm Hg and diastolic blood pressure less than 85 mm Hg. The primary outcome was the combined endpoint of time to doubling of entry serum creatinine, end-stage renal disease, or death. Secondary outcomes included fatal and nonfatal cardiovascular events. A Clinical Management Committee monitored the conduct of the study. An Outcome Confirmation Committee classified all study outcome events in blinded fashion. An external Data Safety Monitoring Committee monitored unblinded data for interim safety and efficacy analyses of the study. Eligibility criteria included informed consent, age 30 to 70 years, adult-onset diabetes, hypertension, urine protein excretion greater than 900 mg/24 hours, and serum creatinine values of 90 to 265 micromol/L in women and 110 to 265 micromol/L in men. Baseline characteristics were age, 59 +/- 8 years; body mass index, 31 +/- 7 kg/m(2); 67% male; 73% white, 14% black, and 13% other; duration of diabetes, 15 +/- 9 years; retinopathy, 66%; neuropathy, 48%; congestive heart failure, 7.5%; screening seated systolic blood pressure, 156 +/- 18 mm Hg, and diastolic blood pressure, 85 +/- 11 mm Hg; urine protein excretion, 4.0 +/- 3.5 g/24 hours; serum creatinine, 150 +/- 53 micromol/L; serum potassium, 4.6 +/- 0.5 mEq/L; total cholesterol, 229 +/- 58 mg/dL; and hemoglobin A(1c), 8.1 +/- 1.7%. This large-scale international trial should help define the clinical course and standards of care for hypertensive adults with type 2 diabetes mellitus and nephropathy. Results available on May 19, 2001, will help in defining the current controversy of the risks and benefits of blockade of the renin-angiotensin system versus calcium channel blockade versus standard antihypertensive therapy in this large patient population.

Evolving strategies for renoprotection: diabetic nephropathy

A cumulative incidence of diabetic nephropathy of 25-40% has been documented after duration of diabetes of at least 25 years in both type 1 and type 2 diabetic patients. Diabetic nephropathy has become the leading cause (25-44%) of end-stage renal failure in Europe, the United States and Japan. Until the early 1980s, no renoprotective treatment was available for use in diabetic nephropathy. Death occurred on average 5-7 years after the onset of persistent proteinuria. It should be recalled that development of treatment modalities occurred in reverse order: in the early 1980s, antihypertensive treatment of diabetic nephropathy was introduced, and in the early 1990s, primary and secondary prevention with improved glycaemic control and angiotensin-converting enzyme inhibition. The two main treatment strategies for primary prevention of diabetic nephropathy are improved glycaemic control and blood pressure lowering, particularly using drugs such as angiotensin-converting enzyme inhibitors. Megatrials and meta-analyses have clearly demonstrated the beneficial effect of both the above-mentioned treatment modalities. Secondary prevention, that is, treatment modalities applied to diabetic patients with high risk of development of diabetic nephropathy (e.g. those with microalbuminuria) has been documented, applying angiotensin-converting enzyme inhibitors in both type 1 and type 2 diabetic patients. Furthermore, improved metabolic control reduces the risk of progression. In special cases (such as pancreas transplantation) even reversal of diabetic glomerular lesions has been documented. Antihypertensive treatment of patients with overt nephropathy induces a reduction in albuminuria, a reduction in the rate of decline of glomerular filtration rate, delays development of end-stage renal failure and improves survival. Many potential treatment modalities in preventing and treating diabetic nephropathy are presently being evaluated.

Ramipril prolongs life and is cost effective in chronic proteinuric nephropathies

BACKGROUND

Our objectives were to predict the long-term cost and efficacy of the angiotensin-converting enzyme, ramipril, in patients with nondiabetic chronic nephropathies.

METHODS

The time to end-stage renal disease (ESRD) was predicted by two different models based on the rate of glomerular filtration rate decline (DeltaGFR) and incidence of ESRD (events) measured during the Ramipril Efficacy in Nephropathy Trial in 117 and 166 patients, respectively, randomized to comparable blood pressure control with ramipril or conventional therapy. Direct medical costs of conservative and renal replacement therapy were estimated by a payer perspective, and cases more and less favorable to ramipril were computed by a sensitivity analysis. The study took place at the Clinical Research Center for Rare Diseases, "Aldo & Cele Daccò," Bergamo, Italy. Patients included those with chronic, nondiabetic nephropathies and persistent urinary protein excretion rate >/=3 g/24 h. Time to ESRD, survival, and direct costs of conservative and renal replacement therapy are discussed.

RESULTS

Both in the DeltaGFR-based or events-based models, ramipril delayed progression to ESRD and prolonged patient survival by 1.5 to 2.2 and 1.2 to 1.4 years, respectively, and saved $16,605 to $23,894 lifetime and $2, 422 to $4203 yearly direct costs per patient. Even in the less favorable hypotheses, ramipril allowed lifetime and yearly cost savings that exceeded 10 to 11 and 20 to 40 times, respectively, the additional costs related to prolonged survival.

CONCLUSIONS

In our study population, ramipril prolongs life while saving money because of its beneficial effect on the course of nondiabetic chronic nephropathies.