During the past decade social scientists as well as physicians have shown increased interest in the problem of how differences in doctor-patient relationships1 may lead to variations in compliance2 on the part of patients. As the growing literature attests, there is no dearth of relevant theoretical formulations; however, empirical studies which present data to support existing analyses are relatively sparse. Moreover, little attention has been given to identification of other sources of influence which, along with the interaction between the doctor and patient, may play a part in determining whether or not patients follow their physicians' instructions. Indeed, the doctor-patient relationship has sometimes been approached as if it operated within a vacuum in which *Abridged and revised from part of a larger report by Milton S. Davis entitled Factors Affecting Perceived Compliance with the Medical Regimens Established for Heart Patients by Their Physicians, unpublished Ph.D. dissertation, Purdue University, 1962. The data used in this report were collected as part of the Purdue Farm Cardiac Project co-sponsored by Purdue University, Indiana Heart Association, American Heart Association, Indiana State Board of Health and the National Heart Institute. A more complete description of the project is contained in Proceedings of the Purdue Farm Cardiac Seminar, W. H. M. Morris, editor, Purdue University, Agricultural Experiment Station, Lafayette, Indiana, September, 1958. The authors are indebted to G. J. Kallas, W. H. M. Morris, D. C. Riedel, and L. Turgeon for their assistance in either the collection, analysis or presentation of these data. tCornell University Medical College :Department of Sociology, Purdue University 1. As early as 1935 L. J. Henderson called attention to the doctor-patient relationship as a social system. (Physician and Patient as a Social New England Journal of Medicine, 212, 1935, pp. 819-825). More recently, Parsons in his various articles dealing with medical sociology has characterized the patient Social System, Glencoe, Illinois: The Free Press, 1951), the physician (Illness and the Role of the Physician, American Journal of Orthopsychiatry, 21, 1951, pp. 425-460), and the role which the family plays in illness (Talcott Parsons and Renee Fox, Illness, Therapy and the Modern Urban Family, Journal of Social Issues, 8, 1952, pp. 31-44). Bales points out that socio-structural factors lead to changes in social relationships in such a way that a certain indifference, impersonality and emotional neutrality become institutionalized as explicit obligations in the performance of particular roles, including that of the doctor with his patient. (Robert F. Bales, Small Groups: Studies in Social editor, A. Paul Hare, et al., New York: Alfred A. Knopf, 1955). Dilemmas in the doctor-patient relationship have been discussed by Eliot Freidson (Patients' Views of Medical Practice, New York: Russell Sage Foundation, 1961) and R. H. Blum Management of the DoctorPatient Relationship, New York: McGraw Hill Company, 1960). In an intensive study of 50 doctorpatient relationships, Lois Pratt, Arthur Seligman and George Reader (Physician's View of the Level of Medical Information Among Patients, American Journal of Public Health, 47, 1957, pp. 1277-1283) focus on the give and take in the interaction. Of particular interest is the question of communication of information between clinic patients and physicians. Gene Levine, (The Good Physician: A Study of Physician-Patient Interaction, Working Paper No. 3, Evaluation Studies of the Cornell Comprehensive Care and Teaching Program, Bureau of Applied Social Research, Columbia University, 1957) in another intensive study of doctor-patient relationships, identified a number of role attributes and obligations which govern the practicing physician. Henry Lennard and Arnold Bernstein Anatomy of Psychotherapy, New York: Columbia University Press, 1961) in an intensive analysis of 500 sessions from eight individual psychotherapies applied social science concepts and methods to describe interaction and systems of relationships for the purpose of understanding the structure of therapeutic communication. 2. Other investigators have been directly concerned with compliance in the medical regimens. Harold Roth and David Berger (Studies of Patient Cooperation in Ulcer Treatment, I. Observation of Actual as Compared to Prescribed Antacid Intake on a Hospital Ward, Gastroenterology, 38, 1960, pp. 630-633) found that patients with peptic ulcer