HOW DO ANESTHESIOLOGISTS SELECT PATIENTS WHEN INTRODUCING A NEW DRUG INTO PRACTICE

As part of the marketing strategy for the anesthetic drug propofol (Di privan(R)), Stuart Pharmaceuticals began a Phase IV postmarketing stud y soon after the drug received Food and Drug Administration approval i n 1989. We used data from this study to test the hypothesis that anest hesiologists would initially use propofol for young, relatively health y patients and then, with experience, for older, sicker patients. The Phase IV study involved 1722 institutions, 1819 anesthesiologists, and 25,981 patients. The study incorporated three sequential steps, each to be tested in five patients. In Step 1, propofol was used for induct ion only; in Step 2, for induction and maintenance of anesthesia by in termittent injection; and, in Step 3, for induction and maintenance by continuous infusion. Inclusion criteria were age 18-80 yr and ASA phy sical status I-III. Exclusion criteria were continuing pregnancy and a previous adverse anesthetic experience. Physicians used standardized data collection forms to voluntarily compile detailed demographic, per ioperative, and outcome variables for patients. Data were then evaluat ed by an independent, multicenter team of seven anesthesiologists and three epidemiologists to determine whether the first two patients sele cted to participate in each step (Patients 1 and 2, 6 and 7, and 11 an d 12) were less sick, younger, or undergoing less invasive or shorter procedures than patients enrolled later in the same steps (Patients 4 and 5, 9 and 10, and 14 and 15). Physicians gave propofol first to pat ients with fewer concurrent diseases than are found in the general pop ulation (10% were hypertensive versus 16%; 3% were diabetic versus 10% ). As the study progressed to Steps 2 and 3, slightly, but only slight ly, sicker and older patients were enrolled. Although this pattern per tained to the group as a whole, not all physicians followed it. Of the three most serious adverse events (one death and two cardiac arrests) , two occurred in patients older than 90 yr of age. Institutions at wh ich one or more physicians began Step 3 before completing Step 2 were labeled ''innovative.'' Comparison revealed that physicians at innovat ive institutions introduced the drug in slightly older, sicker patient s than did physicians at noninnovative institutions. This study sugges ts that anesthesiologists are conservative in the selection of patient s for the introduction of a new drug.