Penicillin in Treatment of Diphtheria

The first figure to the right of the equation is a function purely of the number of cases in each group. The second figure is an estimate, in the form of a regression coefficient, of the logarithm of the rate of clearance of each particular group-a figure which varies from epidemic to epidemic. The difference between these two regression coefficients0.01627-is an index of the difference in rate of clearance between the two groups. This figure can be shoWn to be highly significant statistically, its standard error being 0.003338, giving a " t " of 4.88 and a probability for 12 degrees of freedom which is less than 0.001. The figures compare favourably with the formula obtained by Hartley and Martin: Log,, y=2.6002-0.0218 x