PHYSICIANS BEHAVIOR AND THEIR INTERACTIONS WITH DRUG COMPANIES - A CONTROLLED-STUDY OF PHYSICIANS WHO REQUESTED ADDITIONS TO A HOSPITAL DRUG FORMULARY

Objective.-It is controversial whether physicians' interactions with d rug companies affect their behavior. To test the null hypothesis, that such interactions are not associated with physician behavior, we stud ied one behavior: requesting that a drug be added to a hospital formul ary. Design.-Nested case-control study. Setting.-University hospital. Participants.-Full-time attending physicians. Case physicians were all 40 physicians who requested a formulary addition from January 1989 th rough October 1990. Control physicians were 80 randomly selected physi cians who had not made requests. Main Exposure Measure.-Physician inte ractions with drug companies, as determined by survey of physicians (r esponse rate, 88% [105/120]). Results.-Physicians who had requested th at drugs be added to the formulary interacted with drug companies more often than other physicians; for example, they were more likely to ha ve accepted money from companies to attend or speak at educational sym posia or to perform research (odds ratio [OR], 5.1; 95% confidence int erval [CI], 2.0 to 13.2). Furthermore, physicians were more likely tha n other physicians to have requested that drugs manufactured by specif ic companies be added to the formulary if they had met with pharmaceut ical representatives from those companies (OR, 13.2; 95% CI, 4.8 to 36 .3) or had accepted money from those companies (OR, 19.2; 95% CI, 2.3 to 156.9). These associations were consistent in multivariable analyse s controlling for potentially confounding factors. Moreover, physician s were more likely to have requested formulary additions made by the c ompanies whose pharmaceutical representatives they had met (OR, 4.9; 9 5% CI, 3.2 to 7.4) or from whom they had accepted money (OR, 1.7; 95% CI, 1.0 to 2.7) than they were to have requested drugs made by other c ompanies. Conclusion.-Requests by physicians that drugs be added to a hospital formulary were strongly and specifically associated with the physicians' interactions with the companies manufacturing the drugs.