Economic evaluation variable costs

A problem long appreciated in economic evaluations, but whose seriousness has perhaps been underestimated (Sturm et al, 1999), is that a sample size sufficient to power a clinical evaluation may be too small for an economic evaluation. This is mainly because the economic criterion variable (cost or cost-effectiveness) shows a tendency to be highly skewed. (One common source of such a skew is that a small proportion of people in a sample make high use of costly in-patient services.) This often means that a trade-off has to be made between a sample large enough for a fully powered economic evaluation, and an affordable research study. Questions also need to be asked about what constitutes a meaningful cost or cost-effectiveness difference, and whether the precision (type I error) of a cost test could be lower than with an effectiveness test (O Brien et al, 1994). 

To evaluate design options and carry out preliminary process optimization, simple economic criteria are required. What happens to the revenue from product sales after the process has been commissioned The sales revenue first pays for fixed costs which are independent of the rate of production. Variable costs, which do depend on the rate of production, also must be met. After this, taxes are deducted to leave the net profit. 

The variable operating costs include the consumption of feed + fuel, cooling water and electricity. For their evaluation, it was taken into account that in the actual economic scenario the costs of such a scheme are mainly related to those of the natural gas and of the plant thermal efficiency. The evaluation is reported in Table 9.3. 

There are really no new considerations introduced into the model from a computational viewpoint when economic variables are included. There are, of course, certain conceptual difficulties which arise because of questions as to proper costs or realizations to be used in specific problems. These are, however, problems in economic evaluation outside the scope of this chapter. 

The scope of the economic evaluation includes estimation of capital cost figures for a nitric add plant producing 280 tonnes/day of a 60% product. Following this capital cost estimation the total annual operating costs are estimated, both variable and fixed components being considered. Also considered is the cost of providing finance for the initial capital outlay at 25% interest per annum. 

In economic evaluations, there is a need to make assumptions about the variables in the analysis. For instance, assumptions that are made commonly include the incidence of adverse effects, the drug s efficacy (in clinical trials) and effectiveness (use in actual practice), and the costs of drugs or other direct medical costs. It is important to keep in mind that assumptions are simply predictions about what a researcher thinks might happen as a result of a program or intervention. To account for the variety of outcomes that may arise in any intervention, researchers should use a technique known as... 

It may be necessary to improve membrane selectivities, so that further purification of the produced hydrogen before re-use in the desulphurisation units can be limited as far as possible. Moreover the membrane reactor can be optimised for various variables, such as H2S conversion, hydrogen recovery, membrane area and temperature. In a techno-economic evaluation combined with advanced process design the impact of different operating parameters on the investment and operating costs should be studied. 

Despite the limitations of many of the articles as true economic evaluations, this literature contains a wealth of information pertinent to the clinical practice of pharmacy that serves to document innovative and successful experiences and programs. Of importance, we did find that when studies were well conducted (considered true economic evaluations), the results were likely to be favorable that is, the studies were able to demonstrate net savings or positive benefit cost ratios. Because of lack of standardization in reporting of results and variability in study design, it is difficult to make a general statement as to the degree of benefit derived from clinical pharmacy services. However, we were able to abstract calculated benefit cost ratios from the seven applicable studies and describe a range of value from 1.08 1 to 75.84 1 (mean 16.70 1). In other words, for every... 

Various types of economic evaluation are currently undertaken and the terminology is both confusing and somewhat variable. The basic task is to try to link monetary costs to health outcomes in a way which permits rational choices between therapies to be made. Torrance identifies five major types of study (Torrance, 1996). 

Process variants are to be modeled mathematically to evaluate them quantitatively. For this purpose a process is modeled by process elements and by their interlinks as they appear due to flows of energy and mass. The mathematical evaliration of the process model for ary given instance is denoted simulation of the process. Process simulations allow for assessment of the fixed and variable costs, the design of process equipment, of the necessary utihties, and thus for the assessment of the economic viability of the process variants. 

Economic evaluation - one main challenge is to bring MES out of the laboratory to technical application. At the early stage of the development, a rough calculation should at least include the assessment of needed productivities at the given fixed and variable costs (e.g., for reactor, electrodes, membranes, reaction medium, pretreatment of the gas). The volumetric productivities (space-time yields), final product concentrations, and total process times determine the overall process performance. These parameters should be used to define operational windows for the production of bulk chemicals. Furthermore, this theoretical approach allows the identification of limiting process parameters. 

Surface estimating aids presented by many paint suppliers are not valid for economic evaluation of paint systems - the true surface areas form the base for estimates (texture, undulation, fasteners, flanges, etc.). For appropriate evaluation of a particular paint system, the most important factor is its maintenance cost per square meter per year, and this consideration should be coupled with the serviceability of the paint system in variable conditions (e.g. change of cargo in a ship or similar). 

In summary, economic analysis of medical technology or medical care evaluates a medical service by comparing its monetary cost with its monetary benefit (cost-benefit), by measuring its monetary cost in relation to its outcomes (cost-effectiveness), or simply by tabulating the costs involved (cost-identification). Direct costs are generated as services are provided. In addition, productivity costs should be considered, especially in determining the benefit of a service that decreases morbidity or mortality. Finally, the perspective of the study determines the costs and benefits that will be quantified in the analysis, and sensitivity analyses test the effects of changes in variable specifications for estimated measures on the results of the study. 

Estimation of column costs for preliminary process evaluations requires consideration not only of the basic type of internals but also of their effect on overall system cost. For a distillation system, for example, the overall system can include the vessel (column), attendant structures, supports, and foundations auxiliaries such as reboiler, condenser, feed neater, and control instruments and connecting piping. The choice of internals influences all these costs, but other factors influence them as well. A complete optimization of the system requires a full-process simulation model that can cover all pertinent variables influencing economics. 

As with many therapeutic decisions, economic cost both to the individual and to society mnst be considered. Currently, the annual cost of the new potentially disease-modifying therapies is considerable. The cost to the pharmacist of glatiramer and both currently available interferons is between 10,000 and 17,000 per patient per year. Given this expense, it must be remembered that these therapies are not curative and that individual patients may experience variable results. Future investigations evaluating these therapeutic modahties clearly will need to address not only chnical but also economic and humanistic outcomes. 

To develop and monitor any aspect of drug policies - which naturally include cost containment - one needs to collect reliable and valid data on processes and outcomes. This chapter focuses on the data needed to detect and evaluate the impact of a drug policy on the different elements of drug management and delivery. Important variables relate to the various aspects of prescribing, dispensing and consumption, but also to the ultimate consequences in terms of health and finance. The types of data discussed in this chapter therefore include facts and hgures on pharmaceutical expenditure, utilization, price, health and economics outcomes, as well as data on the pharmaceutical industry. 

Results for the three graphite-moderated reactors previously discussed will be presented, since they represent three stages of evolution for the gas-cooled reactor and because physics data on the fuel cycle exist for each of the concepts. Uranium ore cost is generally the most uncertain parameter in fuel cycle cost evaluations and, consequently, has been chosen as a variable unless otherwise indicated. The basic economic assumptions for the calculations are shown in Table XI, together with... 

The variability in energy savings and capital costs still depends on the existing evaporator conditions. For existing multi-effect units in which the total amount of first-effect vapor is now used in the second effect, the choice and location of the steam-jet thermocompressor are more complicated because the heat balances and heat-transfer rates are affected for each evaporator reaction. The economics may still be favorable to justify the technical evaluation and modification. Since the limitations of steam-jet thermocompressors are a compression ratio below 1.8 and new heat-transfer rates, the first effect normally becomes the best location. 

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