1907 Journal of the American Medical Association (JAMA)  
logic relations of rheumatism have been drawn from hospital statistics, and it further shows that a "general hospital population" is constituted differently from a normal population. This really opens up the whole question of disease statistics and suggests that many of them, being based on studies of hospital patients rather than on the normal population, probably contain serious errors.
doi:10.1001/jama.1907.02530090056011 fatcat:olvivjifebh7dikwfdxqi6pax4