Estimation of Input Costs for a Markov Model in a German Health Economic Evaluation of Newer Antidepressants.

Background: Estimating input costs for Markov models in health economic evaluations requires health state-specific costing. This is a challenge in mental illnesses such as depression, as interventions are not clearly related to health states. We present a hybrid approach to health state-specific cost estimation for a German health economic evaluation of antidepressants. Methods: Costs were determined from the perspective of the community of persons insured by statutory health insurance ("SHI insuree perspective") and included costs for outpatient care, inpatient care, drugs, and psychotherapy. In an additional step, costs for rehabilitation and productivity losses were calculated from the societal perspective. We collected resource use data in a stepwise hierarchical approach using SHI claims data, where available, followed by data from clinical guidelines and expert surveys. Bottom-up and top-down costing approaches were combined. Results: Depending on the drug strategy and health state, the average input costs varied per patient per 8-week Markov cycle. The highest costs occurred for agomelatine in the health state first-line treatment (FT) ("FT relapse") with €506 from the SHI insuree perspective and €724 from the societal perspective. From both perspectives, the lowest costs (excluding placebo) were €55 for selective serotonin reuptake inhibitors in the health state "FT remission." Conclusion: To estimate costs in health economic evaluations of treatments for depression, it can be necessary to link different data sources and costing approaches systematically to meet the requirements of the decision-analytic model. As this can increase complexity, the corresponding calculations should be presented transparently. The approach presented could provide useful input for future models.

Effectiveness and cost-efficacy of phosphate binders in hemodialysis.

OBJECTIVES: Worldwide, incidence rates of chronic renal insufficiency have clearly increased over the past decade, especially in people of older age. Hyperphosphatemia is the strongest independent risk factor for mortality in renal patients. In order to reduce serum phosphate concentrations to recommended values, phosphate binders (P binders) are used to bind ingested phosphate in the digestive tract. Besides the traditional therapies with calcium and aluminium salts, sevelamer and lanthanum represent recent developments on the market. The purpose of the present health technology assessment (HTA) report was to compare the effectiveness and safety of different P binders in patients with chronic renal insufficiency. METHODS: Based on a systematic literature search followed by a two-part selection process with predefined criteria 18 publications were included in the assessment. RESULTS: All P binders effectively controlled serum phosphate, calcium and parathyroid hormone concentrations. The numbers of hypercalcemic episodes were higher when using calcium-containing P binders compared to sevelamer and lanthanum. Regarding mortality rate, cardiovascular calcification and bone metabolism no definite conclusions could be drawn; however, sevelamer seemed to be more effective than calcium in certain patient subgroups, such as older patients and patients with preexisting arterial calcification. CONCLUSIONS: From a medical point of view, sevelamer showed superiority over calcium-containing P binders at least for special indications.

Effectiveness and cost-efficiency of phosphate binders in hemodialysis.

HEALTH POLITICAL BACKGROUND: In 2006, the prevalence of chronic renal insufficiency in Germany was 91,718, of which 66,508 patients were on dialysis. The tendency is clearly growing. SCIENTIFIC BACKGROUND: Chronic renal insufficiency results in a disturbance of the mineral balance. It leads to hyperphosphataemia, which is the strongest independent risk factor for mortality in renal patients. Usually, a reduction in the phosphate intake through nutrition and the amount of phosphate filtered out during dialysis are not sufficient to reduce the serum phosphate values to the recommended value. Therefore, phosphate binders are used to bind ingested phosphate in the digestive tract in order to lower the phosphate concentration in the serum. Four different groups of phosphate binders are available: calcium- and aluminium salts are the traditional therapies. Sevelamer and Lanthanum are recent developments on the market. In varying doses, all phosphate binders are able to effectively lower phosphate concentrations. However, drug therapies have achieved recommended phosphate levels in only 50 percent of patients during the last years. RESEARCH QUESTIONS: How effective and efficient are the different phosphate binders in chronic renal insufficient patients? METHODS: The systematic literature search yielded 1,251 abstracts. Following a two-part selection process with predefined criteria 18 publications were included in the assessment. RESULTS: All studies evaluated conclude that serum phosphate, serum calcium and intact parathyroid hormone can be controlled effectively with all phosphate binders. Only the number of episodes of hypercalcaemia is higher when using calcium-containing phosphatebinders compared to Sevelamer and Lanthanum. Regarding the mortality rate, the cardiovascular artery calcification and bone metabolism no definite conclusions can be drawn. In any case, the amount of calcification at study start seems to be crucial for the further development of the cardiovascular calcification. Economic studies show higher costs for Sevelamer and Lanthanum compared to calcium-containing phosphate binders. DISCUSSION: Only a few well documented primary studies on the effectiveness of phosphate binders are available. Particularly long-term studies with a robust study design and transparent documentation are lacking. Ten of the eleven primary studies included in this report were conducted in only 539 patients from five patient collectives. CONCLUSIONS: From a medical point of view, Sevelamer shows some superiority over calcium-containing phosphate binders based on the current data, at least for special indications. The validity of the present Health Technology Assessment (HTA) report is significantly limited due to the limited number of available publications, the low sample size of treated patients, as well as the fact that the majority of studies are based on the same patient collectives. Prospective long-term studies not funded by the industry with adequate sample sizes and comparable study designs are called for to make authoritative statements regarding the medical effectiveness and safety of Sevelamer and Lanthanum, as well as regarding their economic efficiency.