Logical analysis of clinical medicine. Part 1.

UK : University of London, 1975.

1 encoded moving image (38 min.) : sound, black and white.

00:38:23

University of London

Unrestricted

CC-BY-NC

Creative Commons Attribution-Non-Commercial 2.0 UK: England & Wales

In English

Presented by Professor Wilfrid Card, University of Glasgow. Produced by David Sharp.

This video is one of around 310 titles, originally broadcast on Channel 7 of the ILEA closed-circuit television network, given to Wellcome Trust from the University of London Audio-Visual Centre shortly after it closed in the late 1980s. Although some of these programmes might now seem rather out-dated, they probably represent the largest and most diversified body of medical video produced in any British university at this time, and give a comprehensive and fascinating view of the state of medical and surgical research and practice in the 1970s and 1980s, thus constituting a contemporary medical-historical archive of great interest. The lectures mostly take place in a small and intimate studio setting and are often face-to-face. The lecturers use a wide variety of resources to illustrate their points, including film clips, slides, graphs, animated diagrams, charts and tables as well as 3-dimensional models and display boards with movable pieces. Some of the lecturers are telegenic while some are clearly less comfortable about being recorded; all are experts in their field and show great enthusiasm to share both the latest research and the historical context of their specialist areas.

Segment 1 Opening titles and opening quotations from Roger Bacon, Gottfried Wilhelm Leibniz and Karl Pearson regarding the relationship between Mathematics and the sciences. Prof. Card introduces the subject of developing a mathematical structure of medicine. He says that in 1975, there were 55 million people in Britain and an NHS budget of 3 billion pounds. He suggests using decision theory to deploy resources to their best advantage. A chart is shown with an example of a decision tree. He suggests thinking of patients as sets of 'symptoms, signs, radiological and laboratory data'. A definition of 'indicant', a word that covers all of these, is shown. A case study of dyspepsia is discussed, and an indicant is shown. Time start: 00:00:00:00 Time end: 00:04:30:00 Length: 00:04:30:00

Segment 2 Card continues to discus the case study, emphasising the need for taking the patient's history without forgetting anything. A patient is seen being asked questions by a computer. Card discusses how this method was developed. A voiceover is heard discussing whether patients are favourable to being interrogated by computers rather than doctors. He says that they feel that computer interrogation is the future. Another patient is seen on the telephone answering questions asked by a computer. Time start: 00:04:30:00 Time end: 00:09:43:00 Length: 00:05:13:00

Segment 3 Card continues to discuss diagnosing dyspepsia. He also discusses the need for grading illnesses such as has been done for dyspnoea. He then talks about allocating patients to a 'disease class' once a history has been taken. He also talks about assigning patients to 'treatment classes'. He mentions typhoid fever as an example of a disease that has clear defining characteristics. However, classification can be problematic. Time start: 00:09:43:00 Time end: 00:14:06:20 Length: 00:04:23:20

Segment 4 Abstract images are shown as Card discusses how patients can be characterised in two dimensions but that diseases work in multi-dimensional spaces. He then shows an example of 'cluster analysis' of a group of patients. An example of logical analysis of disease is shown to see if proctocolitis can be separated from Crohn's disease. A biological tree is shown which is used to identify different species. Card then discusses how 'optimal trees' can be used in medicine to diagnose illnesses and determine the probability of a disease in a patient. Time start: 00:14:06:20 Time end: 00:19:58:00 Length: 00:05:52:05

Segment 5 Card shows how new information gathered can be used to re-calculate the probability of a disease. The example of a man with jaundice is given. A graph is seen, showing the probabilities of different diseases for the patient. He also discusses how the probabilities at each step of diagnosis can be used to determine the next test on the patient. Mathematical tables are displayed, showing matrices of probabilities. Time start: 00:19:58:00 Time end: 00:25:37:00 Length: 00:05:39:00

Segment 6 Card discusses the importance of error rates in logical diagnosis. A table is shown, displaying error rates of three consultants and a computer diagnosing the same patient. He discusses the data in relation to error rates. He then talks about the effects of error rates on the evidence doctors try to collect. He discusses how to measure weight of evidence and uses a case study of a patient with gastrointestinal problems. He also discusses how to plot the loss of weight of evidence against error rates with the aid of some mathematical charts. Time start: 00:25:37:00 Time end: 00:31:28:22 Length: 00:05:51:22

Segment 7 Card talks about how people recognise patterns. He says that symptoms are also a pattern, and shows a list of symptoms, asking the audience to diagnose carcinoma of the head of the pancreas from them. He then discusses how to analyse pattern recognition using the concept of dependent probabilities. He explains independence using a film of playing cards and dice and then discusses independent and dependent probabilities in relation to symptoms in a patient. Time start: 00:31:28:22 Time end: 00:38:23:06 Length: 00:06:54:09