Interpretation of and preference for probability expressions among Japanese patients and physicians.

ed from enriched probability expressions in the Japanese language. Although probability expressions are abundant, we might have a bigeminal or two-phased recognition of probability, that is a rough classification and a finer modification. Attitudes towards numbers and words Although patient preference for probability expressions is a matter of concern, how content both patients and physicians are with the status quo and which probability expressions both groups prefer should be considered. Previous studies on patient preference for numbers or words have not been conclusive. Woloshin et al. found that patients preferred quantitative to qualitative information.2 Mazur and Hickam, however, reported the opposite results.8 The present study found that Japanese patients prefer qualitative to quantitative terms, as did Mazur and Hickam, whereas the preference of physicians was opposite. Our study revealed a discrepancy between patients and physicians in the assessment of physicians’ actual expressions of probability. Patients did not think that physicians used numbers in clinical situations as frequently as physicians themselves thought. Patients might give weight to and listen attentively to qualitative expressions, ignoring physicians’ use of numbers, or physicians tend to place more value on numbers and overestimate using quantitative expressions. At any rate, physicians should recognize this discrepancy when referring to probability. Pertinent usage of words The best way to communicate with patients regarding probability should be carefully thought out. Because of the inherent vagueness of qualitative probability terms, three choices are available: quantify probabilities whenever possible,5,6 use qualitative and quantitative estimates together1,2 or codify interpretations of qualitative expressions.4,10 Codifying vague expressions does not appear to be a realistic solution according to the inconsistency described above, lack of consensus and difficulties of the task, among others. Considering that most patients preferred words to numbers, we believe that both numbers and words should be provided when faced with critical decision making. Confirmation of mutual understanding is of course mandatory in most of the clinical situations.