Computerized medical records and preventive health care: Success depends on many factors

objective: To study the effect of a computerized medical record and other practice factors on the delivery of preventive health care. design: Prospective, controlled trial. setting: University general internal medicine teaching clinic. participants: Forty-five internal medicine residents and their 4 supervising attending physicians. intervention: The study group used a computerized ambulatory medical record system that included health care maintenance reminders. The control group used a conventional paper record with a health care maintenance flow sheet. measurements and main results: The computer reminders significantly increased health care maintenance recommendations made to patients for proctosigmoidoscopy, tetanus vaccination, influenza vaccination, and pneumococcal vaccination, but not for fecal occult blood testing, mammography, Pap smears, or serum thyroxme screening in the elderly. First-year residents were nearly twice as successful as third-year residents in overall health care maintenance. Success scores varied markedly depending on which attending physician was supervising the residents. We found a strong interaction among group assignment, supervising attending, and level of training such that the reminders doubled success scores among firstyear residente supervised by two of the attending physicians but had little effect on other subgroups. The time of year and the format of the reminder also had important effects for some of the maneuvers. conclusions: Although computerized medical records markedly unproved the performance of prevention maneuvers by committed physicians, many physicians using computer systems failed to make use of the resource. The reasons for this were complex. Future work in this area should carefully control for personal behaviors and focus upon administrative changes that more effectively implement these potentially powerful tools.