Papers on Medicine, Public Health and Sanitation 87 



2. Errors in diagnosis. Errors iii diagnosis are com- 

 mon, and especially when the germ of a disease is not 

 surely identified such errors cannot be gTiarded against. 

 Under normal conditions the tendency is to fail to recog- 

 nize such a disease as influenza at least in its milder cases, 

 and so the reported cases would only be a fraction of the 

 whole. On the other hand in the height of an epidemic 

 and especially of a great pandemic the psychological ef- 

 fect results in calling anything approaching influenza in 

 nature a genuine case. It is quite possible, then, that the 

 reported cases would exceed the true number. 



3. Health authorities are often negligent in collecting 

 and forivarding reports of communicable disease. Thus 

 in Pope County during the year studied there were re- 

 ported less cases of influenza than there were deaths from 

 the disease. Statistics based chiefly upon morbidity re- 

 ports are therefore very misleading. 



4. Death Certificates. In Death Certificates we are 

 exposed to the same errors in diagnosis as for morbidity 

 reports. In addition a large proportion of Illinois physi- 

 cians do not make out their Death Certificates properly. 

 Fatal influenza is almost invariably connected with pneu- 

 monia. The proper certificate should give influenza as 

 the cause of death and pneumonia as the contributory 

 cause or complication. This is not the arbitrary ruling 

 of the State Department of Public Health ; it is in accord 

 with the rulings of the U. S. Census Bureau, and Avith the 

 rules laid down by the international committee. Never- 

 theless, in one County Medical Society meeting, where 

 the question was asked, fifteen out of the sixteen present 

 said they would give pneumonia as the cause of death. 

 In many of these certificates, although the real cause of 

 death was influenza, there has been no mention of in- 

 fluenza as related to the case. 



All certificates giving pneumonia or bronchopneumonia 

 as the cause of death are questioned by our Department. 

 It is the experience of the U. S. Bureau of Census, of our 

 own Department and of other investigators that such 

 questions result in a decided reduction in the number of 

 deaths recorded for pneumonia and a corresponding in- 



