Clinical decision limits

Weinstein M, Fineberg H, Elstein A, et al. Clinical decisions and limited resources. In Weinstein M, editor. Clinical decision analysis. Philadelphia Saunders, 1980. pp. 228-265. 

If our patient is older than, younger than, sicker than, healthier than, ethnically different from, taller, shorter, simply different from the subjects of a study, do the results pertain ...No degree of evidence will fully chart the expanse of idiosyncrasy in human health and disease. Thus, to work skillfully with evidence is to acknowledge its limits. All of the art and all of the science of medicine depends on how artfully and scientifically we as practitioners reach our decisions. The art of clinical decision making is judgment, an even more difficult concept to grapple with than evidence (pp. xi, xvii). 

A maximal concentration of cTnl or cTnl exceeding the decision limit, defined as the 99th percentile of values for a reference control group, on at least one occasion during the first 24 hours after the index clinical event. 

The lack of specificity of total AMY measurement has led to the interest in the direct measurement of P-AMY instead of total enzyme activity for the differential diagnosis of patients with acute abdominal pain. By applying the best decision limit (i.e., an activity equal to threefold the upper reference limit), the clinical specificity of P-AMY for the diagnosis of acute pancreatitis was greater than 90%. The... 

The horizontal services include (but are not limited to) demographic registries, services for dynamic construction of lifetime personal health record, electronic health record management services, global person identification services, clinical and financial data integration services, information management services, electronic collaboration services, clinical decision services, and interdisciplinary coordination services. 

ED requires focused assessments and sound clinical decision-making in a time-pressured environment. However, psychiatric patients don t always fit into the ED s stringent time limits because ... 

But even as leaders use these tools, they can make mistakes of judgment about exactly when and how to employ them. Such mistakes are not limited to the employment of tools they intrude into administrative and clinical decisions as well, where they may lead directly to an increased level of hazard in the working interface and to medical errors. In the next chapter we will explore how cognitive biases can give rise to these errors. 

Laidler, R, Cowan, D.A., Hider, R.C., and Kicman, A.T. (1994) New decision limits and quality-control material for detecting human chorionic gonadotropin misuse in sports. Clinical Chemistry, 40,1306-1311. 

In a tiny fraction of cases, a quick formula can be used. For most cases, the analysis uses an options tree, with one leaf per possible outcome. However, this falls prey to the curse of dimensionality —the number of leaves on the tree grows exponentially in the number of risk and decision dimensions considered. Thus only a limited, simple set of situations can be optimized in this way because one has to severely limit the decisions and risks that are considered. Tools available to help automate and simplify options analysis, widely used in pharmaceutical project evaluation, include Excel addons such as R1SK [11] and more graphically based solutions such as DPL [12]. Both of these support the creation and evaluation of decision trees and of influence diagrams Figure 11.2 shows a simple example of each of these. A primer in applied decision theory is Clemen s book Making Hard Decisions, other sources may be found in the website of James Vornov, Director of Clinical Research at Guildford Pharmaceuticals, a recent convert to decision theory for options analysis [13]. 

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