DIFFICULTIES OF EPIDEMIOLOGICAL STUDIES 



MITCHELL: Dr. McClaughry, do you believe that the data 

 are really not available, or that they have been in a language 

 that is not translatable to your computer language? You are 

 talking about a reporting situation in which the gaps may be 

 far in excess of the words that you need to translate. A mar- 

 riage between the reporting of physicians and the computer re- 

 quires a single common language which permits little or no 

 deviation. 



McCLAUGHRY: The data definitely are not available, since 

 they were not recorded. Of course, the question of translation 

 is also a stickler. Much of the present medical data would be 

 classified by the computer people as "soft garbage", and little 

 would be considered hard data. In recordings of blood pres- 

 sure, for example, Dickinson Richards studied Bellevue Hos- 

 pital records. No correlation was observed between the values 

 found on the clinical charts, which were random measurements, 

 and those measured under well controlled conditions. 



Similarly, in a study done in Julius Comroe's laboratory^, 

 an automatic blood pressure recording device gave entirely 

 different blood pressure levels than those measured in the phy- 

 sician's office. There were patients who had been considered 

 non- progressive hypertensive patients who, with the automatic 

 recorders, were found to be normotensive. 



BLAIR: I am particularly intrigued with the statement of the 

 negative results of hypothermia, and I stress "hypothermia", 

 not "cold exposure". These are two entirely different matters, 

 of course, but we will have to decide with regard to infections 

 whether or not hypothermia has a specific effect upon the or- 

 ganism involved or on the host himself, if he has any resistance 

 at all, 



MARCUS: I questioned some of our thoracic surgeons and 

 found there were four in Salt Lake who engaged in the use of 



1 Richards, D, W., Jr. Personal communication. 



2 Hinmun, A. T., B. T. Engel, and A. F. Bickford. 1962. Am. Heart. J. 63: 663. 



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