Cost effectiveness of ramipril in patients with non-diabetic nephropathy and hypertension: economic evaluation of Ramipril Efficacy in Nephropathy (REIN) Study for Germany from the perspective of statutory health insurance

Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers for adults with early (stage 1 to 3) non-diabetic chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is a long-term condition that occurs as a result of damage to the kidneys. Early recognition of CKD is becoming increasingly common due to widespread laboratory estimated glomerular filtration rate (eGFR) reporting, raised clinical awareness, and international adoption of the Kidney Disease Improving Global Outcomes (KDIGO) classifications. Early recognition and management of CKD affords the opportunity to prepare for progressive kidney impairment and impending kidney replacement therapy and for intervention to reduce the risk of progression and cardiovascular disease. Angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB) are two classes of antihypertensive drugs that act on the renin-angiotensin-aldosterone system. Beneficial effects of ACEi and ARB on kidney outcomes and survival in people with a wide range of severity of kidney impairment have been reported; however, their effectiveness in the subgroup of people with early CKD (stage 1 to 3) is less certain. This is an update of a review that was last published in 2011.

OBJECTIVES

To evaluate the benefits and harms of ACEi and ARB or both in the management of people with early (stage 1 to 3) CKD who do not have diabetes mellitus (DM).

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 6 July 2023 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and Embase, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) reporting the effect of ACEi or ARB in people with early (stage 1 to 3) CKD who did not have DM were selected for inclusion. Only studies of at least four weeks duration were selected. Authors independently assessed the retrieved titles and abstracts and, where necessary, the full text to determine which satisfied the inclusion criteria.

DATA COLLECTION AND ANALYSIS

Data extraction was carried out by two authors independently, using a standard data extraction form. The methodological quality of included studies was assessed using the Cochrane risk of bias tool. Data entry was carried out by one author and cross-checked by another. When more than one study reported similar outcomes, data were pooled using the random-effects model. Heterogeneity was analysed using a Chi² test and the I² test. Results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes and mean difference (MD) and 95% CI for continuous outcomes. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach MAIN RESULTS: Six studies randomising 9379 participants with CKD stages 1 to 3 (without DM) met our inclusion criteria. Participants were adults with hypertension; 79% were male from China, Europe, Japan, and the USA. Treatment periods ranged from 12 weeks to three years. Overall, studies were judged to be at unclear or high risk of bias across all domains, and the quality of the evidence was poor, with GRADE rated as low or very low certainty. In low certainty evidence, ACEi (benazepril 10 mg or trandolapril 2 mg) compared to placebo may make little or no difference to death (any cause) (2 studies, 8873 participants): RR 2.00, 95% CI 0.26 to 15.37; I² = 76%), total cardiovascular events (2 studies, 8873 participants): RR 0.97, 95% CI 0.90 to 1.05; I² = 0%), cardiovascular-related death (2 studies, 8873 participants): RR 1.73, 95% CI 0.26 to 11.66; I² = 54%), stroke (2 studies, 8873 participants): RR 0.76, 95% CI 0.56 to 1.03; I² = 0%), myocardial infarction (2 studies, 8873 participants): RR 1.00, 95% CI 0.84 to 1.20; I² = 0%), and adverse events (2 studies, 8873 participants): RR 1.33, 95% CI 1.26 to 1.41; I² = 0%). It is uncertain whether ACEi (benazepril 10 mg or trandolapril 2 mg) compared to placebo reduces congestive heart failure (1 study, 8290 participants): RR 0.75, 95% CI 0.59 to 0.95) or transient ischaemic attack (1 study, 583 participants): RR 0.94, 95% CI 0.06 to 15.01; I² = 0%) because the certainty of the evidence is very low. It is uncertain whether ARB (losartan 50 mg) compared to placebo (1 study, 226 participants) reduces: death (any-cause) (no events), adverse events (RR 19.34, 95% CI 1.14 to 328.30), eGFR rate of decline (MD 5.00 mL/min/1.73 m2, 95% CI 3.03 to 6.97), presence of proteinuria (MD -0.65 g/24 hours, 95% CI -0.78 to -0.52), systolic blood pressure (MD -0.80 mm Hg, 95% CI -3.89 to 2.29), or diastolic blood pressure (MD -1.10 mm Hg, 95% CI -3.29 to 1.09) because the certainty of the evidence is very low. It is uncertain whether ACEi (enalapril 20 mg, perindopril 2 mg or trandolapril 1 mg) compared to ARB (olmesartan 20 mg, losartan 25 mg or candesartan 4 mg) (1 study, 26 participants) reduces: proteinuria (MD -0.40, 95% CI -0.60 to -0.20), systolic blood pressure (MD -3.00 mm Hg, 95% CI -6.08 to 0.08) or diastolic blood pressure (MD -1.00 mm Hg, 95% CI -3.31 to 1.31) because the certainty of the evidence is very low.

AUTHORS' CONCLUSIONS

There is currently insufficient evidence to determine the effectiveness of ACEi or ARB in patients with stage 1 to 3 CKD who do not have DM. The available evidence is overall of very low certainty and high risk of bias. We have identified an area of large uncertainty for a group of patients who account for most of those diagnosed as having CKD.

Renin-angiotensin-aldosterone pathway modulators in chronic kidney disease: A comparative review

Chronic kidney disease presents a health challenge that has a complex underlying pathophysiology, both acquired and inherited. The pharmacotherapeutic treatment options available today lower the progression of the disease and improve the quality of life but cannot completely cure it. This poses a challenge to the healthcare provider to choose, from the available options, the best way to manage the disease as per the presentation of the patient. As of now, the recommended first line of treatment to control the blood pressure in chronic kidney disease is the administration of renin-angiotensin-aldosterone system modulators. These are represented mainly by the direct renin inhibitor, angiotensin-converting enzyme inhibitors, and angiotensin II receptor blockers. These modulators are varied in their structure and mechanisms of action, hence showing varying treatment outcomes. The choice of administration of these modulators is determined by the presentation and the co-morbidities of the patient, the availability and affordability of the treatment option, and the expertise of the healthcare provider. A direct head-to-head comparison between these significant renin-angiotensin-aldosterone system modulators is lacking, which can benefit healthcare providers and researchers. In this review, a comparison has been drawn between the direct renin inhibitor (aliskiren), angiotensin-converting enzyme inhibitors, and angiotensin II receptor blockers. This can be of significance for healthcare providers and researchers to find the particular loci of interest, either in structure or mechanism, and to intervene as per the case presentation to obtain the best possible treatment option.

Cost-Effectiveness Analysis of Patiromer in Combination with Renin-Angiotensin-Aldosterone System Inhibitors for Chronic Kidney Disease in Sweden

OBJECTIVES

Patients with chronic kidney disease (CKD) are commonly treated with renin-angiotensin-aldosterone system inhibitors (RAASi) in order to delay progression of renal disease. However, research has shown that RAASi in CKD patients increases hyperkalaemia (HK) prevalence, which leads to RAASi discontinuation or dose reduction with the loss of benefits on the kidney. Patiromer is a novel therapy for HK treatment and may enable patients to remain on their RAASi regimen. This study aimed to assess the cost-effectiveness of patiromer from a Swedish healthcare perspective.

METHODS

A Markov model was developed to evaluate the economic outcomes of patiromer versus no patiromer in HK patients with stage 3-4 CKD taking RAASi. The model consisted of six health states reflecting disease progression and hospitalisations. The analysis mainly considered clinical data from the OPAL-HK trial and national costs. The main outcomes of interest were incremental costs (euro [EUR] 2016) and quality-adjusted life years (QALYs), discounted at 3%, and the incremental cost-effectiveness ratio (ICER). Extensive uncertainty analyses were performed.

RESULTS

In comparison to no patiromer, a patiromer patient gained 0.14 QALYs and an incremental cost of EUR 6109 (Swedish krona [SEK] 57,850), yielding an ICER of EUR 43,307 (SEK 410,072)/QALY gained. The results were robust to a range of sensitivity analyses. At a willingness-to-pay threshold of EUR 52,804 (SEK 500,000)/QALY, patiromer had a 50% chance of being cost-effective.

CONCLUSIONS

The results indicate that patiromer may demonstrate value for money in Swedish patients with stage 3-4 CKD, by enabling RAASi treatment. However, there is a considerable degree of uncertainty.

Quality of health economic evaluations for the ACC/AHA stable ischemic heart disease practice guideline: A systematic review

BACKGROUND

The American College of Cardiology/American Heart Association (ACC/AHA) recently published a rigorous framework to guide integration of economic data into clinical guidelines. We assessed the quality of economic evaluations in a major ACC/AHA clinical guidance report.

METHODS

We systematically identified cost-effectiveness analyses (CEAs) of RCTs cited in the ACC/AHA 2012 Guideline for the Diagnosis and Management of Patients with Stable Ischemic Heart Disease. We extracted: (1) study identifiers; (2) parent RCT information; (3) economic analysis characteristics; and (4) study quality using the Quality of Health Economic Studies instrument (QHES).

RESULTS

Quality scores were categorized as high (≥75 points) or low (<75 points). Of 1,266 citations in the guideline, 219 were RCTs associated with 77 CEAs. Mean quality score was 81 (out of 100) and improved over time, though 29.9% of studies were low-quality. Cost-per-QALY was the most commonly reported primary outcome (39.0%). Low-quality studies were less likely to report study perspective, use appropriate time horizons, or address statistical and clinical uncertainty. Funding was overwhelmingly private (83%). A detailed methodological assessment of high-quality studies revealed domains of additional methodological issues not identified by the QHES.

CONCLUSIONS

Economic evaluations of RCTs in the 2012 ACC/AHA ischemic heart disease guideline largely had high QHES scores but methodological issues existed among "high-quality" studies. Because the ACC/AHA has generally been more systematic in its integration of scientific evidence compared to other professional societies, it is likely that most societies will need to proceed more cautiously in their integration of economic evidence.

Proteinuria and clinical outcomes in hypertensive patients

This narrative review focuses on outcomes related to proteinuria in hypertension (HT), and also examines the role of current and future therapeutic strategies. Proteinuria is an independent marker of renal and cardiovascular (CV) disease in hypertensive populations, particularly in high-risk groups such as diabetic patients. Effective blood pressure (BP) control and proteinuria management are associated with significant improvements in the risk of key adverse outcomes, although a causative relationship needs careful assessment. Available antihypertensives have varying effects on proteinuria reduction. Drugs affecting the renin system offer antiproteinuric and renoprotective effects that are probably at least partially independent of their BP effects. Economic evaluations of these interventions confirm their cost-saving benefits relative to other antihypertensives, but outcomes-based research is needed in some settings.

Cost-effectiveness of ACE inhibitor therapy to prevent dialysis in nondiabetic nephropathy: influence of the ACE insertion/deletion polymorphism

INTRODUCTION

End-stage renal disease is associated with high health-care costs and low quality of life compared with chronic kidney disease. The renoprotective effectiveness of angiotensin-converting enzyme inhibitors (ACEi) is largely determined by the ACE insertion/deletion (I/D) polymorphism. We determined the cost-effectiveness of ACEi therapy in nondiabetic nephropathy for the ACE II/ID and for the ACE DD genotype separately. Furthermore, we considered a selective screen-and-treat strategy in which patients are prescribed alternative, more effective, therapy based on their ACE (I/D) polymorphism.

METHODS

Time-dependent Markov models were constructed; cohorts of 1000 patients were followed for 10 years. Data were mainly gathered from the Ramipril Efficacy In Nephropathy trial. Both univariate and probabilistic sensitivity analyses were performed.

RESULTS

ACEi therapy dominated placebo in both the ACE II/ID group (euro15 826, and 0.091 quality-adjusted life years gained per patient) and the ACE DD group (euro105 104 and 0.553 quality-adjusted life years gained). Sensitivity analyses showed 30.2% probability of ACEi being not cost-effective in the ACE II/ID group, against an almost 100% probability of cost-effectiveness in the ACE DD group. A selective screen-and-treat strategy should incorporate an alternative therapy for patients with the ACE II/ID genotype with an at least 9.1% increase in survival time compared with ACEi therapy to be cost-effective. Sensitivity analyses show that higher effectiveness and lower costs of the alternative therapy improve the cost-effectiveness of a screening strategy.

CONCLUSION

ACEi therapy is a cost-saving treatment compared with placebo in nondiabetic nephropathy, irrespective of ACE (I/D) genotype. However, ACEi therapy saved more costs and more health gains were achieved in the ACE DD genotype than in the ACE II/ID genotype. An alternative treatment featuring a modest increase in effectiveness compared with ACEi therapy for patients with the ACE II/ID genotype can be incorporated in a cost-effective or even cost-saving screen-and-treat strategy.

Cost-effectiveness of insulin detemir compared with neutral protamine Hagedorn insulin in patients with type 1 diabetes using a basal-bolus regimen in five European countries

OBJECTIVES

The aim of this analysis was to evaluate the long-term clinical and economic outcomes associated with insulin detemir and neutral protamine Hagedorn (NPH) insulin in combination with mealtime insulin aspart in patients with type 1 diabetes in Belgian, French, German, Italian and Spanish settings.

METHODS

The published and validated IMS CORE Diabetes Model was used to make long-term projections of life expectancy, quality-adjusted life expectancy and direct medical costs. The analysis was based on patient characteristics and treatment effects from a 2-year randomised controlled trial. Events were projected for a time horizon of 50 years. Potential uncertainty using a modelling approach was addressed.

RESULTS

Basal-bolus therapy with insulin detemir was projected to improve quality-adjusted life expectancy by 0.45 years versus NPH in the German setting, with similar improvements in the other countries. Insulin detemir was associated with cost savings in Belgium, Germany and Spain. In France and Italy, lifetime costs were slightly higher in the detemir arm, leading to incremental cost-effectiveness ratios of 519 euro per QALY gained and 3,256 euro per QALY gained, respectively.

CONCLUSIONS

Compared to NPH, insulin detemir is likely to be a dominant treatment strategy in Belgium, Germany and Spain and highly cost-effective in France and Italy in patients with type 1 diabetes.

Cost-effectiveness of pioglitazone in type 2 diabetes patients with a history of macrovascular disease: a German perspective

BACKGROUND

The aim of this study was to project health-economic outcomes relevant to the German setting for the addition of pioglitazone to existing treatment regimens in patients with type 2 diabetes, evidence of macrovascular disease and at high risk of cardiovascular events.

METHODS

Event rates corresponding to macrovascular outcomes from the Prospective Pioglitazone Clinical Trial in Macrovascular Events (PROactive) study of pioglitazone were used with a modified version of the CORE Diabetes Model to simulate outcomes over a 35-year time horizon. Direct medical costs were accounted from a healthcare payer perspective in year 2005 values. Germany specific costs were applied for patient treatment, hospitalization and management. Both costs and clinical benefits were discounted at 5.0% per annum.

RESULTS

Over patient lifetimes pioglitazone treatment improved undiscounted life expectancy by 0.406 years and improved quality-adjusted life expectancy by 0.120 quality-adjusted life years (QALYs) compared to placebo. Direct medical costs (treatment plus complication costs) were marginally higher for pioglitazone treatment and calculation of the incremental cost-effectiveness ratio (ICER) produced a value of euro13,294 per QALY gained with the pioglitazone regimen versus placebo. Acceptability curve analysis showed that there was a 78.2% likelihood that pioglitazone would be considered cost-effective in Germany, using a "good value for money" threshold of euro50,000 per QALY gained. Sensitivity analyses showed that the results were most sensitive to changes in the simulation time horizon. After adjustment for the potential stabilization of pancreatic beta-cell function with pioglitazone treatment, the ICER was euro6,667 per QALY gained for pioglitazone versus placebo.

CONCLUSION

The findings of this modelling analysis indicated that, for patients with a history of macrovascular disease, addition of pioglitazone to existing therapy reduces the long-term cumulative incidence of diabetes-complications at a cost that would be considered to represent good value for money in the German setting.

Evaluating the cost-effectiveness of therapy conversion to insulin detemir in patients with type 2 diabetes in Germany: a modelling study of long-term clinical and cost outcomes

OBJECTIVES

To evaluate the long-term cost-effectiveness of transferring type 2 diabetes patients to an insulin detemir regimen after failure to achieve adequate control with oral antidiabetic agents (OADs) alone, or in combination with neutral protamine hagedorn (NPH) insulin, or with insulin glargine in Germany.

METHODS

A computer simulation model of diabetes was used to make long-term projections of future clinical outcomes and direct medical costs based on findings from a German subanalysis of the PREDICTIVE trial. The study analysed the impact of converting patients failing their current treatments to an insulin detemir regimen. Therapy conversion to insulin detemir +/- OADs was associated with a significant reduction in glycosylated haemoglobin (HbA(1)c) compared with OADs alone, NPH insulin +/- OADs, and insulin glargine +/- OADs. Across all three groups, hypoglycaemia rates decreased by 80% and patients lost an average of 0.9 kg of body weight during treatment with insulin detemir +/- OADs.

RESULTS

Therapy conversion to insulin detemir +/- OADs was projected to improve life expectancy by 0.28 years compared with OADs alone, and by 0.13 years compared with the NPH and glargine regimens. Transfer to insulin detemir was associated with improvements in quality-adjusted life expectancy of 0.21 quality-adjusted life years (QALYs) over OADs alone, 0.28 QALYs over NPH +/- OADs, and 0.29 QALYs over glargine +/- OADs. Insulin detemir was associated with savings over patient lifetimes due to reduced diabetes-related complications in all three comparisons.

CONCLUSIONS

Therapy conversion to insulin detemir +/- OADs in type 2 diabetes patients failing OADs alone, NPH or insulin glargine regimens was associated with improvements in life expectancy, quality-adjusted life expectancy and cost savings in all three scenarios evaluated.

Estimating the cost effectiveness of ramipril used for specific clinical indications: comparing the outcomes in four clinical trials with a common economic model

BACKGROUND AND OBJECTIVES

Economic analyses of drug therapies are highly dependent on the clinical indications for treatment. The cost effectiveness of ramipril has been evaluated in numerous studies, usually based on the results of one specific clinical trial. We estimated the cost effectiveness of this drug across a range of currently accepted therapeutic indications, using a single health economic model and adjusted for quality of life, to compare the different outcomes observed in four clinical trials.

METHODS

The cardiovascular life expectancy model, a validated Markov model, was calibrated to accurately forecast the results of four trials including AIRE, HOPE, Micro-HOPE, and REIN. We then extrapolated these results over the remaining life expectancy of the patients enrolled in each study and adjusted for the quality of life associated with the observed outcomes. The cost per quality-adjusted life-year (QALY) was then calculated from the perspective of the Canadian healthcare system incorporating the estimated direct healthcare costs associated with treatments and outcomes.

RESULTS

After discounting all costs and outcomes 3% annually, the benefits associated with ramipril ranged from 0.74 QALYs in the AIRE study to 1.22 QALYs in Micro-HOPE. Treatment was estimated to be cost-saving for some patient groups, such as those in REIN. The highest cost-effectiveness ratio was observed among individuals enrolled in HOPE ($Can20 000 per QALY in 2002).

CONCLUSION

Treatment with ramipril appears to be economically attractive across a wide range of patient groups, including those with increased coronary risk and/or diabetes mellitus (HOPE and Micro-HOPE), those with congestive heart failure (AIRE), and those with non-diabetic nephropathy (REIN).

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.

Cost-effectiveness of pharmacogenetic testing to predict treatment response to angiotensin-converting enzyme inhibitor

OBJECTIVE

This study aimed to assess the potential cost-effectiveness of testing patients with nephropathies for the I/D polymorphism before starting angiotensin-converting enzyme (ACE) inhibitor therapy, using a 3-year time horizon and a healthcare perspective.

METHODS

We used a combination of a decision analysis and Markov modeling technique to evaluate the potential economic value of this pharmacogenetic test by preventing unfavorable treatment in patients with nephropathies. The estimation of the predictive value of the I/D polymorphism is based on a systematic review showing that DD carriers tend to respond well to ACE inhibitors, while II carriers seem not to benefit adequately from this treatment. Data on the ACE inhibitor effectiveness in nephropathy were derived from the REIN (Ramipril Efficacy in Nephropathy) trial. We calculated the number of patients with end-stage renal disease (ESRD) prevented and the differences in the incremental costs and incremental effect expressed as life-years free of ESRD. A probabilistic sensitivity analysis was conducted to determine the robustness of the results.

RESULTS

Compared with unselective treatment, testing patients for their ACE genotype could save 12 patients per 1000 from developing ESRD during the 3 years covered by the model. As the mean net cost savings was euro 356,000 per 1000 patient-years, and 9 life-years free of ESRD were gained, selective treatment seems to be dominant.

CONCLUSION

The study suggests that genetic testing of the I/D polymorphism in patients with nephropathy before initiating ACE therapy will most likely be cost-effective, even if the risk for II carriers to develop ESRD when treated with ACE inhibitors is only 1.4% higher than for DD carriers. Further studies, however, are required to corroborate the difference in treatment response between ACE genotypes, before genetic testing can be justified in clinical practice.

A French cost-consequence analysis of the renoprotective benefits of irbesartan in patients with type 2 diabetes and hypertension

OBJECTIVES

We performed a cost-consequence analysis in a French setting of the renoprotective benefit of irbesartan in hypertensive type 2 diabetes patients over a 25-year period.

RESEARCH DESIGN AND METHODS

A previously published Markov model simulated progression from microalbuminuria to overt nephropathy, doubling of serum creatinine, end-stage renal disease and death. Three treatment strategies with analogous blood pressure control were compared: (A) control--conventionally medicated antihypertensive therapy (excluding angiotensin converting enzyme inhibitors, other angiotensin-2-receptor antagonists and dihydropyridine calcium channel blockers) initiated at microalbuminuria; (B) early irbesartan--(300 mg daily added to control, initiated with microalbuminuria) and (C) late irbesartan--(300 mg daily, initiated with overt nephropathy). Probabilities came from the Irbesartan in Reduction of Microalbuminuria-2 study, Irbesartan in Diabetic Nephropathy Trial and other sources. Clinical and economic outcomes were projected over 25 years. Annual discount rates were 3%.

RESULTS

Compared to control, early use of irbesartan added (mean +/- standard deviation) 1.51 +/- 0.08 undiscounted life years (discounted: 0.94 +/- 0.05 years), while late irbesartan added 0.07 +/- 0.01 (0.04 +/- 0.01) years/patient. Early irbesartan added 1.03 +/- 0.06 discounted quality-adjusted life years (QALYs), while late irbesartan added 0.06 +/- 0.01 QALYs. Early and late irbesartan treatments were projected to save 22,314 +/- 1273 euro and 6619 +/- 820 euro/patient, respectively versus control. Sensitivity analysis showed that even over short time horizons both irbesartan treatments were superior to the control group.

CONCLUSIONS

In France, early irbesartan treatment improved quality and length of life and reduced costs in hypertensive patients with type 2 diabetes and microalbuminuria. Late irbesartan therapy is beneficial, but earlier irbesartan leads to better outcomes.

The role of renin-angiotensin-aldosterone system in the progression of chronic kidney disease

The renin-angiotensin-aldosterone system (RAAS) is a well known regulator of blood pressure (BP) and determinant of target-organ damage. It controls fluid and electrolyte balance through coordinated effects on the heart, blood vessels, and Kidneys. Angiotensin II (AII) is the main effector of the RAAS and exerts its vasoconstrictor effect predominantly on the postglomerular arterioles, thereby increasing the glomerular hydraulic pressure and the ultrafiltration of plasma proteins, effects that may contribute to the onset and progression of chronic renal damage. AII may also directly contribute to accelerate renal damage by sustaining cell growth, inflammation, and fibrosis. Interventions that inhibit the activity of the RAAS are renoprotective and may slow or even halt the progression of chronic nephropathies. ACE inhibitors and angiotensin II receptor antagonists can be used in combination to maximize RAAS inhibition and more effectively reduce proteinuria and GFR decline in diabetic and nondiabetic renal disease. Recent evidence suggests that add-on therapy with an aldosterone antagonist may further increase renoprotection, but may also enhance the risk hyperkalemia. Maximized RAAS inhibition, combined with intensified blood pressure control (and metabolic control in diabetics) and amelioration of dyslipidemia in a multimodal approach including lifestyle modifications (Remission Clinic), may achieve remission of proteinuria and renal function stabilization in a substantial proportion of patients with proteinuric renal disease. Ongoing studies will tell whether novel drugs inhibiting the RAAS, such as the renin inhibitors or the vasopeptidase inhibitors, may offer additional benefits to those who do not respond, or only partially respond, to this multimodal regimen.

Review of the cost of diabetes complications in Australia, Canada, France, Germany, Italy and Spain

OBJECTIVES

To provide a comprehensive source document on previously published cost data for diabetic complications in Australia, Canada, France, Germany, Italy and Spain for use in a peer-reviewed, validated diabetes model.

METHODS

A search for published cost of diabetes complications data was performed in peer-reviewed journals listed in PubMed and health economic conference proceedings from 1994 to March 2005. Where country specific data were not available, we referred to government websites and local cost experts. All costs were inflated to 2003 Euros (E). Major complication costs are presented.

RESULTS

First year costs of non-fatal myocardial infarction varied between E19277 in Spain and E12292 in Australia. In subsequent years of treatment, this range was E1226 (France) to E203 (Australia). Angina costs were similar across all four countries: E1716 in Australia; E2218 in Canada; E2613 in France; E3342 in Germany; E2297 in Italy; and E2207 in Spain. Event costs of non-fatal stroke were higher in Canada (E23173) than in other countries (Australia E13443; France E11754; Germany E19399; Italy E6583; Spain E4638). Event costs of end-stage renal disease varied depending on the type of dialysis: in Australia (E17188-27552); Canada (E33811-58159); France (E24608-56487); Germany (E46296-68175); Italy (E43075-56717); and Spain (E28370-32706). Lower extremity amputation costs were: E18547 (Australia); E17130 (Canada); E31998 (France); E22096 (Germany); E10177 (Italy); and E14787 (Spain).

CONCLUSIONS

Overall, our search showed costs are well documented in Australia, Canada, France and Germany, but revealed a paucity of data for Spain and Italy. Spanish costs, collected by contacting local experts and from government reports, generally appeared to be lower for treating cardiovascular complications than in other countries. Italian costs reported in the literature were primarily hospitalization costs derived from diagnosis-related groups, and therefore likely to misrepresent the cost of specific complications. Additional research is required to document complication costs in Spain and Italy. Australian and German values were collected primarily by referring to diagnostic related group (DRG) tariffs and, as a result, there may be a need for future economic evaluations measuring the accuracy of the costs and resource utilization in the reported values. These cost data are essential to create models of diabetes that are able to accurately simulate the cumulative costs associated with the progression of the disease and its complications.

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.

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.

Cost effectiveness of ramipril in patients at high risk for cardiovascular events : economic evaluation of the HOPE (Heart Outcomes Prevention Evaluation) study for Germany from the Statutory Health Insurance perspective

BACKGROUND

In the HOPE (Heart Outcomes Prevention Evaluation) trial, ramipril (compared with placebo) significantly reduced cardiovascular death and all-cause mortality as well as the incidence of costly cardiovascular events, such as myocardial infarction, revascularisation, stroke, cardiac arrest, hospitalisation due to heart failure and worsening angina pectoris, new-onset diabetes mellitus and microvascular diabetic complications.

OBJECTIVE

Data from the HOPE study were used in a cost-effectiveness analysis to determine the additional cost per life-year gained (LYG) when the ACE inhibitor ramipril was added to the current medication of patients at high risk for cardiovascular events. The aim was to establish the incremental cost-effectiveness ratio (ICER) of ramipril versus placebo from the perspective of the Statutory Health Insurance (SHI) provider in Germany, for both the study population as a whole and for the subgroup of patients with diabetes.

DESIGN

A modelling approach was used, based on secondary analysis of published data and retrospective application of costs. In the base-case analysis, average case-related expenses of the SHI were applied and LYG were quantified using the average of the difference between the survival rates in the ramipril and placebo groups during the HOPE trial. LYG beyond the trial duration were estimated by the method of declining exponential approximation of life expectancy.

RESULTS

After a treatment period of 4.5 years, the ICER of ramipril versus placebo was Euros 4074/LYG and Euros 2486/LYG (discounted at 5% per annum and in 1998-2002 values; Euro 1 approximately USD 0.88; first quarter 2002 values) for the HOPE study population as a whole and the subgroup of patients with diabetes, respectively. To test the model's robustness, the influence of the model variables on the results was quantified using a deterministic model, and a best-case/worst-case scenario analysis. The effect of random variables was investigated in a Monte Carlo simulation. The acquisition cost for ramipril had the greatest impact on the ICER of ramipril (2.2-fold greater than the impact of the number of LYG). In 95% of the 10,000 simulation steps, the ICER of ramipril after 4.5 years of treatment was between Euros 1290 and Euros 9005 per LYG for the entire HOPE study population and between Euros 290 and Euros 6115 per LYG in the diabetic subgroup.

CONCLUSIONS

Results of this evaluation suggest that ramipril is likely to be cost effective in secondary prevention of cardiovascular events from the perspective of the SHI (third-party payer) in Germany. The estimated ICER of ramipril compares well with other ICERs of widely accepted treatments used for the management of cardiovascular diseases, such as HMG-CoA reductase inhibitors.