PREVENTIVE MEDICINE * 
By Marx FE. Boyp, M. D. 
Preyentive medicine may be defined as that branch of applied 
biology which seeks to reduce or eradicate disease by removing or 
altering the responsible etiological factors. Included within its 
scope are two subjects which are often confused with it; these are 
hygiene and sanitation, respectively. Hygiene is the proper care 
of the body to permit the normal functioning of the various 
organs and tissues, while sanitation is the proper cleanliness of the 
environment. 
Since preventive medicine requires a complete knowledge of the 
etiology of disease for its application, it is apparent that deficiencies 
of etiologic knowledge must necessarily limit the scope of successful 
work. There are, however, five groups of disease whose etiology is 
sufficiently well known to warrant their classification as preventable. 
The groups are: 
1. Diseases produced as the result of the invasion of the body by 
microorganisms; 
2. Diseases the result of a faulty or deficient diet; 
3. Diseases the result of unhygienic or insanitary conditions of 
employment; 
4, Diseases arising as the result of the puerperal state; and 
5. Diseases transmitted from parent to offspring. 
_ Despite the fact that the number of diseases included in the above 
groups is limited, this handicap is very much reduced by the fact 
that the diseases included in the above groups are for the most part 
of considerable importance as causes of morbidity and mortality, so 
that effective control measures directed against them will accomplish 
a great deal in reducing the hazards of life. Their importance may 
be judged from the following mortality statistics from the registra- 
tion area of the United States: 
Papen 7 1912 1913 
Per cent of total population of United States in registration 
pe Wet ote _ yee ye el Fb d ee oe ret he ee ee a 63. 2 65.1 
Hataile Geminss “All. CAlSe@Se oo! «2 a oe 838, 251 890, 848 
MeAthse cases of Group bw eee ee A 287,645 304, 580 
Heaths: disease of Groupr 22-222. oN se a eet 4,409 15,005 
Deaths, Gisedse of (Group BL. sul) tie ei a eee 156 171 
Deaths /Giseasefof Group d.45o3 2072-3 04- fe eee 9,035 10,010 
Heath weisease: Of GrOuih poe se ee ak Not a direct cause 
of death. 
17This article forms Chapter I, Introduction, of the book entitled ‘‘ Preventive Medicine,” 
by Mark F. Boyd, M. D., published by W. B. Saunders Sa cae Philadelphia and London, 
and is here reprinted with their permission. 
513 
