Guidelines based on fear of type II (false-negative) errors. Why we dropped the pulse check for lay rescuers.

The new guidelines for CPR and ECC strongly emphasize evidence as the basis for all new clinical recommendations. The level of evidence may range from a high of Level 1 (one or more randomized, controlled clinical trials) to a low of Level 8 (rational conjecture, common sense, or accepted historically as standard practice). Nonevidence factors can influence the selection of the final class of recommendation, such as the expense of interventions, the ease of teaching, and the consequences of error. A technique that might improve resuscitation outcomes based on animal evidence, eg, openchest CPR, turns out to be complex, difficult to learn, and difficult to implement. Such a technique would not merit as strong a recommendation as a technique that produced more modest improvements in survival but did so with superior ease of teaching, learning, and implementing. Two principles that were less familiar to the International Guidelines 2000 experts came into play in several of the debates over the final class of recommendation: