The computer as a consultant

What we talk about when we talk about risk: refining surgery's hazards in medical thought

CONTEXT

Current efforts to improve the cost-effectiveness of health care focus on assessing accurately the value of technologically complex, costly medical treatments for individual patients and society. These efforts universally acknowledge that the determination of such value should incorporate information regarding the risks posed by a given treatment for an individual, but they typically overlook the implications for medical decision making that inhere in how notions of risk are understood and used in contemporary medical discourse. To gain perspective on how the hazards of surgery have been defined and redefined in medical thought, we examine changes over time in notions of risk related to operative care.

METHODS

We reviewed historical writings on risk assessment and patient selection for surgical procedures published between 1957 and 1997 and conducted informal interviews with experts. To examine changes attributable to advances in research on risk assessment, we focused on the period surrounding the 1977 publication of an influential surgical risk-stratification index.

FINDINGS

Writings before 1977 demonstrate a summative, global approach to patients as "good" or "poor" risks, without quantifying the likelihood of specific postoperative events. Beginning in the early 1980s, assessments of operative risk increasingly emphasized quantitative estimates of the probability of dysfunction of a specific organ system after surgery. This new approach to establishing surgical risk was consistent with concurrent trends in other domains of medicine. In particular, it emphasized a more "scientific," standardized approach to medical decision making over an earlier focus on individual physicians' judgment and professional authority.

CONCLUSIONS

Recent writings on operative risk reflect a viewpoint that is more specific and, at the same time, more generic and fragmented than earlier approaches. By permitting the separation of multiple component hazards implicit in surgical interventions, such a viewpoint may encourage a distinct, permissive standard for surgical interventions that conflicts with larger policy efforts to promote cost-effective decision making by physicians and patients.

Three decades of research on computer applications in health care: medical informatics support at the Agency for Healthcare Research and Quality

The Agency for Healthcare Research and Quality and its predecessor organizations-collectively referred to here as AHRQ-have a productive history of funding research and development in the field of medical informatics, with grant investments since 1968 totaling $107 million. Many computerized interventions that are commonplace today, such as drug interaction alerts, had their genesis in early AHRQ initiatives. This review provides a historical perspective on AHRQ investment in medical informatics research. It shows that grants provided by AHRQ resulted in achievements that include advancing automation in the clinical laboratory and radiology, assisting in technology development (computer languages, software, and hardware), evaluating the effectiveness of computer-based medical information systems, facilitating the evolution of computer-aided decision making, promoting computer-initiated quality assurance programs, backing the formation and application of comprehensive data banks, enhancing the management of specific conditions such as HIV infection, and supporting health data coding and standards initiatives. Other federal agencies and private organizations have also supported research in medical informatics, some earlier and to a greater degree than AHRQ. The results and relative roles of these related efforts are beyond the scope of this review.

The CCC system in two teaching hospitals: a progress report

Computing systems developed by the Center for Clinical Computing (CCC) have been in operation in Beth Israel and Brigham and Women's hospitals for over 10 years. Designed to be of direct benefit to doctors, nurses, and other clinicians in the care of their patients, the CCC systems give the results of diagnostic studies immediately upon request; offer access to the medical literature: give advice, consultation, alerts, and reminders; assist in the day-to-day practice to medicine, and participate directly in the education of medical students and house officers. The CCC systems are extensively used, even by physicians who are under no obligation to use them. Studies have shown that the systems are well received and that they help clinicians improve the quality of patient care. In addition, the CCC systems have had a beneficial impact on the finances of the two hospitals, and they have cost less than what many hospitals spend for financial computing alone.

Performance of four computer-based diagnostic systems

BACKGROUND

Computer-based diagnostic systems are available commercially, but there has been limited evaluation of their performance. We assessed the diagnostic capabilities of four internal medicine diagnostic systems: Dxplain, Iliad, Meditel, and QMR.

METHODS

Ten expert clinicians created a set of 105 diagnostically challenging clinical case summaries involving actual patients. Clinical data were entered into each program with the vocabulary provided by the program's developer. Each of the systems produced a ranked list of possible diagnoses for each patient, as did the group of experts. We calculated scores on several performance measures for each computer program.

RESULTS

No single computer program scored better than the others on all performance measures. Among all cases and all programs, the proportion of correct diagnoses ranged from 0.52 to 0.71, and the mean proportion of relevant diagnoses ranged from 0.19 to 0.37. On average, less than half the diagnoses on the experts' original list of reasonable diagnoses were suggested by any of the programs. However, each program suggested an average of approximately two additional diagnoses per case that the experts found relevant but had not originally considered.

CONCLUSIONS

The results provide a profile of the strengths and limitations of these computer programs. The programs should be used by physicians who can identify and use the relevant information and ignore the irrelevant information that can be produced.

Medical diagnostic decision support systems--past, present, and future: a threaded bibliography and brief commentary

Articles about medical diagnostic decision support (MDDS) systems often begin with a disclaimer such as, "despite many years of research and millions of dollars of expenditures on medical diagnostic systems, none is in widespread use at the present time." While this statement remains true in the sense that no single diagnostic system is in widespread use, it is misleading with regard to the state of the art of these systems. Diagnostic systems, many simple and some complex, are now ubiquitous, and research on MDDS systems is growing. The nature of MDDS systems has diversified over time. The prospects for adoption of large-scale diagnostic systems are better now than ever before, due to enthusiasm for implementation of the electronic medical record in academic, commercial, and primary care settings. Diagnostic decision support systems have become an established component of medical technology. This paper provides a review and a threaded bibliography for some of the important work on MDDS systems over the years from 1954 to 1993.

Computer aided interpretation of acid-base disorders

This paper describes an expert system for the interpretation of acid-base disorders. The target users are residents in training in internal medicine, anaesthesia and intensive care medicine. The program is written in PROLOG and runs on a SUN 3/160 minicomputer. Evaluation of a learning set (N = 202) and a test set (N = 194) has proved that the system's accuracy is acceptable. As a result, the program has recently been put in routine clinical practice.

Clinical computing in a teaching hospital

This report describes a hospital-wide clinical computing system that permits physicians, nurses, medical students, and other health workers to retrieve data from the clinical laboratories; to look up reports from the departments of radiology and pathology; to look up demographic data and outpatient visits; to look up prescriptions filled in the outpatient pharmacy; to perform bibliographic retrieval of the MEDLINE data base; to read, write, retract, edit, and forward electronic mail; and to request delivery of a patient's chart. During a one-week study period, from 300 video display terminals located throughout the hospital, 818 patient care providers used a common registry of 539,000 patients to look up clinical and laboratory data 16,768 times; 477 other hospital workers used the patient registry 46,579 times. In a separate study of 586 health care providers, 470 (80 per cent) indicated that they used computer terminals "most of the time" to look up laboratory results; in contrast, 48 (8 per cent) preferred printed reports. Of 545 hospital workers, 440 (81 per cent) indicated that the computer terminals definitely or probably made their work more accurate, and 452 (83 per cent) indicated that terminals enabled them to work faster. The large amount of use by clinicians and their judgment that the computer has been so helpful to them suggests that a reliable, comprehensive, and easy-to-use computer system can contribute substantially to the quality of patient care.

Computerized medical records. A new resource for clinical decision making

A computerized medical record changes the way a clinician practices medicine by presenting data about patients in multiple organized formats. A computerized record can be used to make it more difficult to overlook important findings. The computer can improve communication by informing both the patient and referring physicians of new data as they become available. Computer graphics or algorithms can be used to emphasize subtle trends. A computer data base can be used to aggregate data about selected patients to provide information about the natural history of disease and effect of treatment.

Standardized diagnosis and treatment of fluid, acid-base and electrolyte disorders in the surgical patient with the aid of a programmable pocket calculator

The approach to fluid, acid-base and electrolyte disorders in the surgical patient has been standardized in a pocket calculator program that categorizes these disorders into formal diagnoses and subsequently uses these diagnoses to determine the appropriate therapy. The program was tested in 80 infusion regimens of patients in the intensive care and surgical wards. The advantages of a standardized approach to these disorders, using diagnostic and therapeutic algorithms, are briefly discussed.

Computers and medical language

This review article presents principles and problems of automated processing of medical language data. Work on automated processing of information in medical language is surveyed. References and a bibliography are provided as an introduction to the field.

Computer use in diagnosis, prognosis, and therapy

Computers are used to influence diagnostic and therapeutic decisions. The computer's information-handling capabilities allow it to serve as a reliable extension of the physician's memory and expander of the physician's information and synthesized knowledge resources. Computers have been used to facilitate decisions through organization of patient data, improved classification of patients, decision analysis in clinical settings, and simulation of expert clinical reasoning. Computer programs are more successful in narrow, constrained, single arenas of medicine with much underlying pathophysiologic understanding and where decisions are based largely on hard laboratory data. New models of synthetic reasoning that simulate expert clinical behavior show promise of supporting complicated decisions concerning problems of multiple diseases. All systems are confronted by problems of consensus and authority of the underlying information used.