Cost-effectiveness of irbesartan/hydrochlorothiazide in patients with hypertension: an economic evaluation for Sweden

Assessing the Consequences of External Reference Pricing for Global Access to Medicines and Innovation: Economic Analysis and Policy Implications

Background: External reference pricing (ERP) is used to set pharmaceutical prices to improve affordability, but its application may have negative consequences on patient access—thus, equity—across countries and on global innovation. With the United States contemplating ERP, negative effects could be magnified. Our aim: identify and quantify some major consequences of ERP. Research design, methods: Besides relying on databases and ERP modelling, we developed a heart failure case study. 4-step approach: 1) review ERP policies; 2) establish worldwide “price corridor”; 3) quantify patient access and health outcomes impact by ERP; 4) estimate ERP impact on innovation.

Results: Our ERP referencing analysis highlights its perverse effects especially in lower-income countries. As counterstrategies to protect their revenues, manufacturers often implement tight list price corridors or launch avoidance/delays. Consequences include suboptimal patient access—hence, worse outcomes—illustrated by our case study: 500,000 + QALYs health loss. Additionally, the ensuing revenue reduction would likely cause innovation loss by one additional medicine that would have benefitted future patients.

Conclusion: This research provides key insights on potential unintentional consequences of medicine price setting by ERP worldwide and under a new proposal for the United States. Our results can inform stakeholder discussions to improve patient access to innovative medicines globally.

The Importance of Model Structure in the Cost-Effectiveness Analysis of Primary Care Interventions for the Management of Hypertension

BACKGROUND

Management of hypertension can lead to significant reductions in blood pressure, thereby reducing the risk of cardiovascular disease. Modeling the course of cardiovascular disease is not without complications, and uncertainty surrounding the structure of a model will almost always arise once a choice of a model structure is defined.

OBJECTIVES

To provide a practical illustration of the impact on the results of cost-effectiveness of changing or adapting model structures in a previously published cost-utility analysis of a primary care intervention for the management of hypertension Targets and Self-Management for the Control of Blood Pressure in Stroke and at Risk Groups (TASMIN-SR).

METHODS

The case study assessed the structural uncertainty arising from model structure and from the exclusion of secondary events. Four alternative model structures were implemented. Long-term cost-effectiveness was estimated and the results compared with those from the TASMIN-SR model.

RESULTS

The main cost-effectiveness results obtained in the TASMIN-SR study did not change with the implementation of alternative model structures. Choice of model type was limited to a cohort Markov model, and because of the lack of epidemiological data, only model 4 captured structural uncertainty arising from the exclusion of secondary events in the case study model.

CONCLUSIONS

The results of this study indicate that the main conclusions drawn from the TASMIN-SR model of cost-effectiveness were robust to changes in model structure and the inclusion of secondary events. Even though one of the models produced results that were different to those of TASMIN-SR, the fact that the main conclusions were identical suggests that a more parsimonious model may have sufficed.

Do Economic Evaluations in Primary Care Prevention and the Management of Hypertension Conform to Good Practice Guidelines? A Systematic Review

Background: Results of previous research have identified the need for further investigation into the compliance with good practice guidelines for current decision-analytic modeling (DAM). Objective: To identify the extent to which recent model-based economic evaluations of interventions focused on lowering the blood pressure (BP) of patients with hypertension conform to published guidelines for DAM in health care using a five-dimension framework developed to assess compliance to DAM guidelines. Methods: A systematic review of English language articles was undertaken to identify published model-based economic evaluations that examined interventions aimed at lowering BP. The review covered the period January 2000 to March 2015 and included the following electronic bibliographic databases: EMBASE and Medline via Ovid interface and the Centre for Reviews and Dissemination’s (CRD) NHS-EED. Data were extracted based on different components of good practice across five dimensions utilizing a framework to assess compliance to DAM guidelines. Results: Thirteen articles were included in this review. The review found limited compliance to good practice DAM guidelines, which was most frequently justified by the lack of data. Conclusions: The assessment of structural uncertainty cannot yet be considered common practice in primary prevention and management of hypertension, and researchers seem to face difficulties with identifying sources of structural uncertainty and then handling them correctly. Additional guidelines are needed to aid researchers in identifying and managing sources of potential structural uncertainty. Adherence to guidelines is not always possible and it does pose challenges, in particular when there are limitations due to data availability that restrict, for example, a validation process.

Comprehensive overview: efficacy, tolerability, and cost-effectiveness of irbesartan

Background

Hypertension represents a major health problem, affecting more than one billion adults worldwide. Irbesartan, an angiotensin II receptor blocker, is considered to be a highly effective treatment in the management of hypertension. The purpose of this review is to evaluate the efficacy, safety and tolerability profile , and cost-effectiveness of treatment with irbesartan in hypertension.

Methods

A review of the literature was conducted using the electronic PubMed and Cochrane Library databases and the Health Economic Evaluations Database of search terms relating to irbesartan efficacy, tolerability, and cost-effectiveness, and the results were utilized.

Results

Findings from the present analysis show that irbesartan either as monotherapy or in combination with other antihypertensive agents can achieve significant reductions in blood pressure, both systolic and diastolic, compared with alternative treatment options. Irbesartan was also found to have a renoprotective effect independent of its blood pressure-lowering in patients with type 2 diabetes and nephropathy. Furthermore, irbesartan demonstrated an excellent safety and tolerability profile , with either lower or equal adverse events compared with placebo and other alternative treatments. In terms of economic analyses, compared with other antihypertensive therapy alternatives, irbesartan was found to be a preferred option, that is less costly and more effective.

Conclusion

The evidence indicates that treating patients with hypertension alone or with type 2 diabetes and nephropathy using irbesartan can control hypertension, prolong life, and reduce costs in relation to existing alternatives.

Evolutionary cost analysis of valsartan initiation among patients with hypertension: a time series approach

OBJECTIVES

This study examines the evolutionary impact of valsartan initiation on medical costs.

METHODS

A retrospective time series study design was used with a large, US national commercial claims database for the period of 2004-2008. Hypertensive patients who initiated valsartan between the ages of 18 and 63, and had continuous enrollment for 24-month pre-initiation period and 24-month post-initiation period were selected. Patients' monthly medical costs were calculated based on individual claims. A novel time series model was devised with monthly medical costs as its dependent variables, autoregressive integrated moving average (ARIMA) as its stochastic components, and four indicative variables as its decomposed interventional components. The number of post-initiation months before a cost-offset point was also assessed.

RESULTS

Patients (n = 18,269) had mean age of 53 at the initiation date, and 53% of them were female. The most common co-morbid conditions were dyslipidemia (52%), diabetes (24%), and hypertensive complications (17%). The time series model suggests that medical costs were increasing by approximately $10 per month (p < 0.01) before the initiation, and decreasing by approximately $6 per month (p < 0.01) after the initiation. After the 4th post-initiation month, medical costs for patients with the initiation were statistically significantly lower (p < 0.01) than forecasted medical costs for the same patients without the initiation.

LIMITATIONS

The study has its limitations in data representativeness, ability to collect unrecorded clinical conditions, treatments, and costs, as well as its generalizability to patients with different characteristics.

CONCLUSIONS

Commercially insured hypertensive patients experienced monthly medical cost increase before valsartan initiation. Based on our model, the evolutionary impact of the initiation on medical costs included a temporary cost surge, a gradual, consistent, and statistically significant cost decrease, and a cost-offset point around the 4th post-initiation month.

Economic evaluation of irbesartan in combination with hydrochlorothiazide in the treatment of hypertension in Greece

OBJECTIVES

Hypertension is a major risk factor for cardiovascular disease and a leading cause of morbidity and mortality. This study evaluates irbesartan in relation to commonly used alternative hypertension therapies losartan and valsartan given in combination with hydrochlorothiazide (HCTZ) in the general hypertensive population in Greece.

METHODS

A Markov model with eight states of health was constructed: hypertension, myocardial infarction (MI), post-MI, angina, stroke, poststroke, heart failure, and death. The model has an annual cycle and estimates mean quality-adjusted survival and treatment cost, which reflect the hypertension treatment and managing cardiovascular events. Risk functions were used to conduct extrapolations. Data on treatment effectiveness, quality of life (QOL) and epidemiology were obtained from published clinical trials and studies. The database of the main Greek National Social Insurance Institute (IKA) was analyzed to estimate the cost of events. The analysis was done from a payer perspective. All outcomes were discounted, and prices correspond to 2008.

RESULTS

The estimated patient cost per annum was stable angina euro 2,252, unstable angina euro 2,572, myocardial infarction euro 2,473, post-MI euro 1,677, stroke euro 12,233, poststroke euro 1,240, heart failure euro 2,655, coronary angiography euro 1,544, percutaneous transluminal coronary angioplasty euro 6,511, and coronary artery bypass graft surgery euro 11,514. For the baseline group (age 57 years, systolic blood pressure 147 mmHg, cholesterol 6.00 mmol/L, body mass index 29) of men with mild to moderate hypertension, for irbesartan, the total treatment cost was euro 15,146, for losartan euro 15,696 and for valsartan euro 15,613; the quality-adjusted life years (QALYs) were irbesartan 12.67, losartan 12.63 and valsartan 12.64. For the baseline group of women with mild to moderate hypertension, the total treatment cost was euro 12,945 for irbesartan, euro 13,424 for losartan and euro 13,379 for valsartan; QALYs were 14.29 for irbesartan, 14.27 for losartan and 14.27 for valsartan. For men with severe hypertension, for irbesartan and losartan, the total treatment cost was euro 18,679 and euro 21,488 and QALYs 12.47 and 12.37, respectively. For women, the total treatment cost was euro 16,202 and euro 19,099 and QALYs 14.16 and 14.09, respectively. Similar results were obtained in relation to other treatment groups in various sensitivity analysis scenarios.

CONCLUSIONS

Based on efficacy data from clinical trials and lower attainment costs in various hypertensive patient populations, irbesartan in combination with HCTZ compares favorably with losartan and valsartan in combination with HCTZ in the Greek setting.