Prior to 1900, laboratory tests were rudimentary, few in number, and often performed by a physician in his office or by a pathologist in hospitals. Epidemic outbreaks of diphtheria, pneumonia, typhoid, and tuberculosis created a demand for additional laboratory tests and individuals to perform them. The increase in civilian and military clinical (hospital) laboratories during World War I and the new American College of Surgeons requirement that hospitals establish a clinical laboratory contributed to a severe shortage of laboratory personnel (Kotlarz, 1998a).
Butina, Michelle; Feltner, Frances J.; and Slone, Melissa, "Medical Laboratory Science Workforce Shortage" (2018). Center of Excellence in Rural Health Workforce Reports. 4.