Statistical studies in immunity : a discussion of the means of estimating the severity of cases of acute disease / by John Brownlee.

  • Brownlee, John, 1868-1927.
Date:
1907
Catalogue details

Licence: In copyright

Credit: Statistical studies in immunity : a discussion of the means of estimating the severity of cases of acute disease / by John Brownlee. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

    12/18 (page 430)
    that when x = Q, y — ^0 per cent, and the branch of zero mortality asymptotic to the positive branch of the axis of x), is ?/ = • This is at best but an approximation, but it is sufficient for the present purposes. Such a formula allows us to determine the position along a base line of cases with a definite death-rate which have been grouped by some other criterion of severity. As a first example, comparison may now be made between the criterion and the day on which patients are first stimulated in typhus fever. The day on which stimulation is first found to be necessary in the course of this disease is a measure of the degree to which the patient’s muscular or nervous equipment of the heart has been poisoned by the disease process. In this case and in all the subsequent examples the numbers are • unfortunately small. To exclude error as far as possible, the numbers stimulated each day have been combined into two series in two day periods and the curve fitted to one of these alternate series by the method of least squares compared with the values of the mortality deduced from the other. It can be seen that the correspondence is very close, showing that a unit of time in the length of illness can be approximately represented by a unit of severity as given by the formula described. The manner in which the distribution fits the curve of severity is shown in Diagram I. both for the rough observations and for the Diagram I. Showing how the actual data from deaths and cases in typhus fever fit themselves to a criterion curve and showing that the day on which a patient is first stimulated corresponds closely to a unit of severity.