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Biomedical subjects

J C Horrocks

Publications and source records attributed to J C Horrocks.

At least 37 records · Page 2Linked to original sources
PubMed1974

Human and computer-aided diagnosis of abdominal pain: further report with emphasis on performance of clinicians.

This paper reports a controlled trial of human and computer-aided diagnosis in a series of 552 patients with acute abdominal pain. The overall diagnostic accuracy of the computer-aided system was 91.5% and that of the senior clinician to see each case was 81.2%. However, the clinician's diagnostic performance improved markedly during the period of the trial. The proportion of appendices which perforated before operation fell from 36% to 4% during the trial, and the negative laparotomy rate dropped sharply. After the trial closed in August 1972 these figures reverted towards their pretrial levels.It is suggested that while computer-aided diagnosis is a valuable direct adjunct to the clinician dealing with the "acute abdomen," he may also benefit in the short-term from the constant feedback he receives and from the disciplines and constraints involved in communicating with the computer.

Abdomen↗
PubMed1973

Clinical diagnostic process: an analysis.

An analysis of observations made during 1,307 diagnoses by a total of 28 clinicians (503 diagnoses in real life, and 804 on simulated patients) concerned primarily the interview of patients suffering from abdominal pain. Interviews ranged from 10 to 35 questions, and from "stereotyped" procedures, in which identical (and often irrelevant) questions were asked to each patient, to "adaptive" interviews, in which specific relevant questions were put to each patient. Senior clinicians tended to ask fewer, more relevant questions than their junior counterparts; and urgent cases were dealt with in a more adaptive fashion than routine cases in outpatients. Disappointingly, there was considerable difference between real-life and simulated situations. From these results it is suggested (a) that the "diagnostic process" does not exist, (b) that any automated diagnostic system must be flexible to accommodate the wishes of a variety of clinicians, and (c) that studies based on artificial clinical situations should be treated with extreme caution.

Abdomen↗
PubMed1972

Computer-assisted diagnosis of abdominal pain using "estimates" provided by clinicians.

This paper reports a comparison between two modes of computer-aided diagnosis in a real-time prospective trial involving 472 patients with acute abdominal pain. In the first mode the computer-aided system analysed each of the 472 patients by referring to data previously collated from a large series of 600 real-life patients. In the second mode the system used as a basis for its analysis "estimates" of probability provided by a group of six clinicians. The accuracy and reliability of both modes were compared with the performance of unaided clinicians.Using "real-life" data the computer system was significantly more effective than the unaided clinician. By contrast, when using the clinicians' own estimates the computer-aided system was often less effective than the unaided clinician-especially when diagnosing less common disorders. It seems, firstly, that future systems for computer-aided diagnosis should employ data from real-life and not clinicians' estimates, and, secondly, that clinicians themselves cannot analyse cases in a probabilistic fashion, since often they have little idea of what the "true" probabilities are.

Abdomen, Acute↗
PubMed1972

Computer-aided diagnosis: description of an adaptable system, and operational experience with 2,034 cases.

This paper describes a system of computer-aided diagnosis using an English Electric KDF9 computer linked to a terminal in a busy clinical department. Data from a series of patients were recorded, coded, and entered into the computer, which then performed a Bayesian analysis and displayed diagnostic probabilities in an adaptable format. Experience in this setting suggests that computer diagnosis may be a valuable aid to the clinician.

Abdomen↗
PubMed1972

Computer-aided diagnosis of acute abdominal pain.

This paper reports a controlled prospective unselected real-time comparison of human and computer-aided diagnosis in a series of 304 patients suffering from abdominal pain of acute onset.The computing system's overall diagnostic accuracy (91.8%) was significantly higher than that of the most senior member of the clinical team to see each case (79.6%). It is suggested as a result of these studies that the provision of such a system to aid the clinician is both feasible in a real-time clinical setting, and likely to be of practical value, albeit in a small percentage of cases.

Abdomen, Acute↗
PubMed1971

Simulation of clinical diagnosis: a comparative study.

This paper presents a comparison between three different modes of simulation of the diagnostic process-a computer-based system, a verbal mode, and a further mode in which cards were selected from a large board. A total of 34 subjects worked through a series of 444 diagnostic simulations.The verbal mode was found to be most enjoyable and realistic. At the board, considerable amounts of extra irrelevant data were selected. At the computer, the users asked the same questions every time, whether or not they were relevant to the particular diagnosis. They also found the teletype distracting, noisy, and slow.The need for an acceptable simulation system remains, and at present our Minisim and verbal modes are proving useful in training junior clinical students. Future simulators should be flexible, economical, and acceptably realistic-and to us this latter criterion implies the two-way use of speech. We are currently developing and testing such a system.

Appendicitis↗
PubMed1971

Production of artificial "case histories" by using a small computer.

This paper describes a method of producing artificial "case histories" by using probability theory and clinical data from a series of 600 patients with acute abdominal pain. A series of 12 such cases were distributed to clinicians, medical students, medical secretaries and technicians, and members of the general public. For each "case" most clinicians concurred with the intended diagnosis. So did the medical secretaries and technicians; indeed this group were more confident of their chosen diagnoses than were the clinicians.It is suggested that clinicians are concerned to a large extent with the consequences of a diagnosis as well as its accuracy, and are motivated to some degree by a fear of the consequences of failure. They may be justified in adopting this policy, for when "errors" in diagnosis are harshly penalized the clinicians were infinitely more effective than any of the other groups.

Abdomen↗