The interaction among the criteria physicians use when prescribing.

A randomly selected sample of Iowa physicians was surveyed using a self-administered mail questionnaire that measured the relative importance of prescribing criteria as well as selected physician and practice characteristics. Based on a response rate 68.3 per cent, it was found that the physicians' criteria for selection of a drug to prescribe could be reduced to two groups. The first group is used to select the generic drug or therapeutic class and is of primary concern to the physicians. Those criteria used in specifying a brand of drug product are of lesser importance to physicians and constitute the second group. It was further discovered that physicians could be segregated into two distinct segments based on the importance of the prescribing criteria. It was not possible, however, to explain the composition of the groups using the physician and practice characters measured.