328
It has, moreover, to be noted here that, in the account of the Arthur Road
Hospital, 53 convalescent patients are not included, who were transferred from other
hospitals which were closed with the decline of the epidemic in 1898. If they be
included, the recovery rate of the Arthur Road Hospital is 26.73 per cent. This
would probably be the correct number for comparison, as no doubt also the Maratha
and Modikhana Hospitals had convalescent admissions in 1898, which are not
separated in the records furnished to me. The surplus on recoveries would be in
such a case 7 per cent. in favour of the Arthur Road Hospital.
Still, as I cannot give the exact number of such convalescent patients admitted
into the other hospitals, I shall not take advantage of the doubt, but base my con-
clusions on the lower recovery rate of 24.29 per cent.
The average recovery rate of 19.76 per cent. in the two other hospitals enables
us to ascertain statistically what advantage the selection gave to the serum treatment.
It is clear that the recovery rate of the non-serum patients of the Arthur
Road Hospital ought to have decreased, if the increase in the recovery rate of the
serum patients was due to the selection.
The recovery rate in the non-serum cases was 19.57 per cent. at the Arthur
Road Hospital and 19.76 per cent. in the patients treated at the other two hospitals.
The difference, therefore, is 0.19 per cent. This difference may be taken as the
numerical expression of the advantage the serum treatment derived from the selec-
tion.
To eliminate this advantage, we have to add this difference to the recovery rate
of the non-serum patients at the Arthur Road Hospital which is then also 19.76 per
cent.
As the recovery rate in the serum caaes is 38.21 per cent. the difference of 18.45
per cent. must be credited to the serum.
This number being based on merely statistical calculations, cannot express the
real efficiency of the serum treatment, because the experiments were not conducted
for statistical purposes.
If we remember that the first principle of selection brought to the serum
treatment cases in which the recovery rate is lower than the average, and that the
second principle excluded, as far as possible, mild cases, in which the rate i.
higher than the average, we arrive at the conclusion that the serum treatment mast
have favoured the results in the non-serum cases.
In fact, such favourable influence is the necessary consequence of the principles
of selection.
Whereas the addition of moribund patients within the limits in which it took
place was irrelevant for the recovery rate of the non-serum cases, this rate had to
increase, because a larger number of mild cases came to the non-serum side than
corresponded to the incidence among the ordinary admissions. Although the advan-
tage the non-serum side thus derived from the selection cannot be put down in
figures, it is real and not to be denied. It helps to explain the fact that the recovery
rate of the non-serum cases is even higher than that of the patients of the intermediate
period, in which the serum was not used, and also that the recovery rate in the non-
serum cases is only 0.19 per cent. lower than that of other hospitals receiving patienta
of better stamina.