EDITOR'S COLUMN

Clinical decisions: How much and how much judgment?

analysis

In this issue, Downs et al. and Lieu et al., in separate arti- cles, tackle a common and difficult clinical problem from the perspective of the epidemiologist. Using the technique of decision analysis, they analyze the main diagnostic and therapeutic options involved in assessing young children for

occult bacteremia in terms of outcome measures. Both studies use data from published studies on occult bactere-

mia to provide basic assumptions for probability calcula- tions, and conclude that all young children with unexplained fever should be treated empirically with antibiotics. For

most clinicians, this is a startling conclusion. Additionally, for those not schooled in epidemiologic and statistical prin- ciples, the logic of the studies is sometimes difficult to fol-

low. The process of decision analysis is, by design, a logical series of steps and assumptions not unlike the process of proving a theorem in geometry. This and similar techniques are being used increasingly in medicine to analyze and evaluate various management strategies in terms of quality of life, risk/benefit ratios, and cost-effectiveness.

The clinician and the epidemiologist share responsibility for ensuring that traditional clinical problem-solving mea- sures and new techniques such as decision analysis are kept in proper balance and complement each other. Mathemat- ical models may be more appropriate for certain types of health issues affecting population groups but less appropri- ate or valid when applied to specific patients or clinical problems. On the other hand, traditional clinical ap- proaches may have significant limitations when applied to health outcome measures of population groups.

The management of occult bacteremia leaves room for debate on both sides. Downs et al. and Lieu et al. have taken the best available published data to reach their conclusions, but these data are not perfect. Accordingly, their findings must be weighed against the judgment of many experienced pediatricians, which does not easily lend itself to decision

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analysis. The traditional clinical approach is a complicated and often subjective process of reasoning and judging based on the personal experiences of the physician and on specific factors in individual cases. The latter include history of ex- posure to infectious agents, selected laboratory values such as a leukocyte count and an absolute neutrophil count, age of the child, height of the fever, time of year, and impres- sion of how "ill appearing" or "sick" the child looks. The last impression is often based on observation in the office or

clinic for several hours. Obviously, both approaches are "playing the odds." The

models of Downs et al. and Lieu et al. are only as valid as

See related articles on pp. 1t and 21.

their assumptions and are limited by the inability to factor in the more subjective aspects of the physician-patient en- counter. These limitations are emphasized when both authors use the term "at risk" for occult bacteremia with- out defining what criteria are associated with being "at risk." For their purposes, "at risk" means having fever. However, the height of the fever may be important, and this is not discussed.

In the final analysis, the clinician can learn to use some of the basic principles of decision analysis to work out rea- sonable approaches to difficult problems. At the same time, proponents of decision analysis, when focusing on specific clinical problems, can emphasize those aspects which do not leave the physician out of the equation. Meanwhile, deter- mining the risk for occult bacteremia in febrile children will continue to challenge us, and until we develop more sensi- tive methods, some children will receive antibiotics on the initial visit and some will not.

Harvey J. Hamrick, MD Assistant Editor

Joseph M. Garfunkel, MD Editor

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