Readers' guide for clinical economics articles: research on value-for-money in medical care
ACP J Club. 1991 Nov-Dec;115:A12. doi:10.7326/ACPJC-1991-115-3-A12
The rising cost of medical care and the limited resources available to pay for it are old news to readers of ACP Journal Club. What is new is that the medical literature is beginning to include research on the cost as well as the effectiveness of medical services. This information can help physicians, patients, and public policy makers assure highquality medical care at a price that the public is willing to pay for identifiable clinical benefits.
This new research on clinical economics is, however, unfamiliar to most physicians, and they need guidance in being critical, prudent users of its information and recommendations. Although some research will help guide clinical decisions, some may be misleading. Articles that simply tally the charges for services without regard for their effectiveness, and then conclude that the least expensive service is preferable, may do more harm than good.
ACP Journal Club will report on economic analyses of medical care only if they meet simple but essential criteria embodied in the questions that follow.
The first question is familiar to critical readers of the medical literature—compared with what? Clinicians always compare alternative strategies, even if one option is to do nothing. They want to know how much more one diagnostic or treatment plan will cost than another and how much more clinical benefit it will provide. These additional (“incremental”) costs and outcomes are essential to determining the cost of every extra unit of clinical outcome (e.g., additional dollars per additional year of life). Reporting only the cost or only the outcome, without comparing them, resembles bookkeeping more than economic analysis and is unlikely to be useful to clinicians. Economics, at its core, is the evaluation of the resources consumed to obtain goods and services and the consideration of alternative uses of limited resources.
Second, readers want to know how cost and effectiveness are measured. Simply adding up the charges for medical services has little to do with true costs unless the charges really reflect the value of all the resources consumed in providing the service, which is rarely the case. Rigorous methods exist for measuring cost and outcomes, and ACP Journal Club readers want to know how reliable the measures are. Knowing the score does not help if one does not know what game is being played and what the rules are. Counting only the charge for a service or using only other visible costs such as prices may mislead the clinician into ignoring the real resources that are used in medical care—the irreplaceable staff time, equipment, supplies, and facilities that could otherwise be deployed in another productive way. The real cost of medical care is the value of the opportunity that is foregone to use limited resources for an alternative purpose, medical or not.
In cost-effectiveness studies, which report the dollars spent per unit of outcome obtained (e.g., dollars per quality-adjusted-year-of-life gained), the validity of measures of effectiveness is just as important as measures of cost. New research methods of evaluating outcome have advanced from the conventional end points in clinical trials (e.g, infections cured, ulcers resolved), and the critical reader wants to be confident of the quality of the methods underlying these new outcome measurements. Valuation is most difficult in costbenefit studies, in which the outcomes of medical care are measured in monetary terms (e.g., the dollar value of the benefits obtained). Valuation is easiest in the simplest form of economic analysis, cost-identification studies, in which the reader can assume that the services being compared are of equal efficacy.
The critical reader also wants to know the point of view of the research: “Whose costs?” and “Benefits for whom?” Because payers, patients, providers, and society as a whole face different costs and may value outcomes differently, these perspectives are specified in a highquality economic analysis of medical care.
Finally, as in all our endeavors, uncertainty remains despite the most careful investigative methods. In clinical economics, when there is uncertainty about the estimates or imprecision in the measurements, sensitivity analyses should be done to determine how sensitive the results are to the data being used. For example, investigators might determine how robust their results are by varying the frequency of hospitalization and its cost if there is uncertainty about their precise values, such as in an economic analysis of treatment for breast cancer. These sensitivity analyses let the reader ask the “so what” question that is familiar to critical readers of the medical literature. If the conclusion is not altered by varying the estimates or measurements that are used from within a study's ranges of uncertainty, then the clinician can feel more comfortable in letting the research guide clinical decision making.
Like other forms of clinical research, economic analyses of medical care can be invaluable to the physician on the cusp of a difficult clinical decision: Is the outcome of this intervention likely to be favorable enough to justify its cost compared with the other options? When carefully done, clinical economics research can help to improve the value for money in medical care.
John M. Eisenberg, MD