Data and methods

Authors of pharmacoeconomic studies should detail the pathway of the health intervention being analysed, preferably with diagrams. In this way, readers can determine whether the proposed flow of health care is comparable to their own method of health care. If not, then the analysis may not be relevant to the reader. The study should be explicit in the types of outcomes used in the analysis, whether it is QALYs, life-years saved, or disease-specific outcomes such as clear scalp. The methods for obtaining cost, effectiveness, and quality-of-life measures should also be clear. If primary data are not available, the assumptions must be clearly stated and a sensitivity analysis performed to make sure that the results of the analysis are robust to these assumptions (see below). A critique of the quality of the input data should also be explicit.

Several general points about cost should be mentioned at this point. The perspective of the study influences the costs used in the analysis. If an analysis is performed from the perspective of the individual patient, then only the costs relevant to the patient should be considered. These costs would include the copay that is involved with the physician visit and the drug, and the time off from work that is needed to see the doctor. Assuming that the drug is covered by insurance, the actual cost of the drug would not be factored since it is irrelevant from the perspective of the patient. On the other hand, third-party payers would be concerned about the cost of the drug as well as the cost of the physician, but not the copay or the time off from work. The analysis performed from the societal perspective would factor in costs that affect all members of society: the cost of the drug, the physician, and the time off from work, as well as any impact on family members.

It is also useful to consider the categories of cost when evaluating a pharmacoeconomic analysis.

Direct healthcare costs are the cost of the resources that directly provide the therapy. These include physicians, medications, laboratory monitoring, radiography, for example.

Indirect costs are those resources that related to time and productivity. Indirect costs include the cost of the consumption of the time that the patient took from work, volunteer time and family-leisure time. It can also include costs associated with the loss of or impaired ability to work secondary to illness.

The theoretically correct manner to estimate cost is by determining the opportunity cost. Opportunity costs consist of the value of forgone benefits; some other programme must have been forsaken in order to pay for a particular therapeutic regimen. For instance, in a hypothetical developing country, it might be necessary to sacrifice an education programme in order to implement a vaccination programme. However, sometimes one cannot assume perfect competition between two competing programmes, so healthcare prices may not approximate true opportunity costs. Instead, health economists use existing market prices to estimate costs. The reader should be wary of analyses that use charges to estimate costs, since charges rarely approximate the market prices of services.

In general, analyses performed from the societal perspective approximate the cost of physician and hospital services by using the Medicare reimbursement rate and estimate the cost of medication using the average wholesale price.

If the study analyses the therapy over a long time course, such as the 10-year outcome of a vaccination programme, then the study needs to outline methods to account for inflation. Also, because, in general, people prefer to have money and benefits now rather than in the future, future costs and benefits in the analysis must be discounted. The Panel on Cost-effectiveness in Health and Medicine has recommended using a 3% discount rate.1"

0 0

Post a comment