Concise and portable in both concept and form, CATs have been adopted by several other institutions and incorporated into their undergraduate and postgraduate training programmes. Because they are patient-based, CATs have appeal to clinical learners at every stage of their careers, from medical students to senior clinicians. Far more educational value comes from creating a CAT than from just reading it second hand. These first drafts may contain inferior evidence, or errors of fact, calculation, or interpretation. This limitation can be transformed into an educational virtue by revising draft CATs in rounds and other educational events, and one feature of our CAT bank in Oxford will be the opportunity for feedback, criticism and revision.
Individual CATs contain a single element of the relevant liter- ature.
Created in busy practices where busy clinicians decide that one piece of critically appraised evidence is better than none, CATs are based on quick searches for at least one useful article, not comprehensive explorations for all useful articles. Individual CATs may have a short shelf life. They become obsolete as soon as newer, better evidence becomes available. Unless they are updated on the basis of this newer, better evidence, their clinical bottom lines become out of date. For this reason, CAT-browsers will be wise to use them as the starting points for updated searches for newer, better evidence.