Biomedical subjects

Stefan Felder

Publications and source records attributed to Stefan Felder.

5 recordsLinked to original sources

PubMed2006

A preference-based measure for test performance with an application to prenatal diagnostics.

Clinical epidemiology generally uses the receiver operating characteristic curve to summarize the accuracy of a diagnostic test and to compare the relative performance of different tests. This paper extends this concept to include the utility gains and losses of true and false test outcomes over the range of a priori risk. A utility index is developed first in situations where test accuracy is exogenously given, second where the test cutpoint can be chosen by the clinician according to the patient's a priori risk and preferences. By integrating over the a priori risk range, we derive an overall measure for a test's performance weighted by utility gains and losses. An example in prenatal diagnostics finally illustrates the clinical uses of the novel approach. Integrating patients' preference into clinical decision making will lead to different cutpoints and different assessments of test performance compared to unweighted policies.

Diagnostic Tests, Routine↗

PubMed2006

Life expectancy and health care expenditures: a new calculation for Germany using the costs of dying.

Some people believe that the impact of population ageing on future health care expenditures will be quite moderate due to the high costs of dying. If not age per se but proximity to death determines the bulk of expenditures, a shift in the mortality risk to higher ages will not affect lifetime health care expenditures as death occurs only once in every life. We attempt to take this effect into account when we calculate the demographic impact on health care expenditures in Germany. From a Swiss data set, we derive age-expenditure profiles for both genders, separately for persons in their last 4 years of life and for survivors, which we apply to the projections of the age structure and mortality rates for the German population between 2002 and 2050 as published by the Statistische Bundesamt. In the extreme case, we assume that morbidity is compressed at the end of life in such a way that a 60-year old in 2050 is as healthy as a 56-year old today if his life expectancy is 4 years higher. We calculate that at constant prices, per-capita health expenditures of Social Health Insurance would rise from 2596 Euro in 2002 to between 2959 Euro and 3102 Euro in 2050 when only the age structure of the population changes and everything else remains constant at the present level, and to between 5232 Euro and 5485 Euro with a technology-driven exogenous cost increase of 1% per annum. A "naïve" projection based only on the age distribution of health care expenditures, but not distinguishing between survivors and decedents, yields values of 3217 Euro and 5688 Euro for 2050, respectively. Thus, the error of excluding the "costs of dying" effect is small compared with the error of underestimating the financial consequences of expanding medical technology.

Aged↗

PubMed2004

Drug price regulation under consumer moral hazard. Two-part tariffs, uniform price or third-degree price discrimination?

Drug price differences across national markets as they exist in the EU are often justified by the concept of Ramsey prices: with fixed costs for R&D, the optimal mark-ups on marginal costs are inversely related to the price elasticity in the individual markets. This well-known result prevails if consumer moral hazard is taken into account. Contrary to the situation without moral hazard, the uniform price does not necessarily dominate discriminatory pricing in welfare terms. The two-part tariff is a better alternative as it allows governments to address moral hazard. A uniform price combined with lump-payments reflecting differences in the willingness to pay and the moral hazard in member states appears to be an attractive option for a common EU drug market.

Cost Control↗

PubMed2004

Data envelopment analysis based bonus payments. Theory and application to inpatient care in the German state of Saxony-Anhalt.

This contribution proposes a reimbursement scheme combining yardstick competition and data envelopment analysis (DEA). The scheme reimburses incurred cost while offering a bonus for resource savings relative to a DEA-based cost norm, providing firms with an incentive to minimize production cost. The individual yardsticks are as close as possible to the actual cost levels, minimizing informational rents of firms. The proposed reimbursement scheme is applied to the hospital sector in Saxony-Anhalt based on data collected in 1999. The results indicate low regulation costs together with potentially large cost reductions due to the incentive structure of the reimbursement scheme.

Germany↗

PubMedDate not supplied

A priori risk and optimal test accuracy in prenatal diagnostics.

The prevalence of fetal chromosome anomalies rises exponentially with the age of the pregnant woman. The risk of fetal anomalies can be specified using biochemical screening tests such as the triple test. This test substantially reduces the number of amniocenteses and proportionally the number of procedure-related miscarriages. However, disadvantages of the triple test include the utility loss of pregnant women who, following a false-negative test result, do not undergo amniocentesis and bear a disabled child as well as the intangible cost of a false-positive triple test. This paper employs a decision-analytic model to reveal the evaluation of this tradeoff, which is implicitly fixed by policy recommendations for a direct amniocentesis at maternal age of 35. It then determines the optimal level of cutoff risk for the triple test, and derives comparative static results: the optimal test accuracy decreases with increasing a-priori risk and increases with a rise in the miscarriage risk and in the woman's preference for detecting an affected fetus as compared to avoiding a miscarriage of an unaffected fetus. These results are in contrast to current clinical practice, where the cutoff of the triple test usually remains fixed.

Adult↗