NONMEDICAL INFLUENCES ON MEDICAL DECISION-MAKING - AN EXPERIMENTAL-TECHNIQUE USING VIDEOTAPES, FACTORIAL DESIGN, AND SURVEY SAMPLING

Objective. To study nonmedical influences on the doctor-patient intera ction. A technique using simulated patients and ''real'' doctors is de scribed. Data Sources. A random sample of physicians, stratified on su ch characteristics as demographics, specialty, or experience, and sele cted from commercial and professional listings. Study Design. A medica l appointment is depicted on videotape by professional actors. The pat ient's presenting complaint (e.g., chest pain) allows a range of valid interpretation. Several alternative versions are taped, featuring the same script with patient-actors of different age, sex, race, or other characteristics. Fractional factorial design is used to select a bala nced subset of patient characteristics, reducing costs without biasing the outcome. Data Collection. Each physician is shown one version of the videotape appointment and is asked to describe how he or she would diagnose or treat such a patient. Principal Findings. Two studies usi ng this technique have been completed to date, one involving chest pai n and dyspnea and the other involving breast cancer. The factorial des ign provided sufficient power, despite limited sample size, to demonst rate with statistical significance various influences of the experimen tal and stratification variables, including the patient's gender and a ge and the physician's experience. Persistent recruitment produced a h igh response rate, minimizing selection bias and enhancing validity. C onclusion. These techniques permit us to determine, with a degree of c ontrol unattainable in observational studies, whether medical decision s as described by actual physicians and drawn from a demographic or pr ofessional group of interest, are influenced by a prescribed set of no nmedical factors.