Speed Quick applicability is another important feature of wellfunctioning heuristics, particularly in emergency situations. After the attacks of September 11, 2001, the Simple

Triage and Rapid Treatment, START,49 a heuristic that can be categorized into the branch of fast-andfrugal trees,50 allowed paramedics to rapidly split the victims into main groups, including Inhibitors,research,lifescience,medical those who required immediate medical treatment and those whose treatment was not as urgent. Accessibility and costs Well-functioning heuristics can be made easily accessible and help treatment and diagnosis even in situations where access to technology is restricted. For instance, for macrolide prescription in young children with community-acquired pneumonia, a tree with only two predictor variables—age and duration of fever—was developed as a decision aid Inhibitors,research,lifescience,medical (Figure 4).51 This frugal decision aid turned out to be only slightly less accurate than a scoring system based on logistic regression (72% versus 75% sensitivity), but using it does not require expensive technology. As a result, this decision aid can be made easily accessible to millions of

Inhibitors,research,lifescience,medical children worldwide, even in poor countries. Figure 4. A fast-and-frugal tree for making decisions about macrolide prescriptions, proposed by Fisher et al51 (see also Katsikopoulos et al.58 for an in-depth discussion). Macrolides are the first-line antibiotic treatment of community-acquired pneumonia. The … Simple heuristics can also aid in saving costs in rich, developed countries, as the following example illustrates. In the US, there are about 2.6 Inhibitors,research,lifescience,medical million emergency room visits each year for dizziness or vertigo.52 Emergency room personnel need to detect the rare instances where such dizziness is due to a dangerous brain stem or cerebellar stroke. MRI with diffusion-weighted imaging can help doctors to make this challenging Inhibitors,research,lifescience,medical diagnosis.

Another diagnostic tool, a simple bedside exam, was developed by Kattah et al.52 An alarm is raised if at least one of three simple tests indicates a stroke. This bedside exam represents a tallying heuristic. In contrast to fast-and-frugal trees and take-the-best, which assign more or less importance to specific predictor variables by ordering them, tallying treats all predictors equally, for example, by simply counting them. out In its general form, tallying can be described as follows. GSK690693 research buy Search rule: Search through predictors in any order. Stopping rule: Stop search after m out of a total of M predictors (with 1 < m < M). If the number of positive predictors is the same for both alternatives, search for another predictor. If no more predictors are found, guess. Decision rule: Decide for the alternative that is favored by more predictors. As it turns out, Kattah et al’s52 simple bedside exam yields a larger sensitivity than MRI, while the false-positive rate is only slightly larger than that of the MRI, which did not raise any false alarms.