The use of reference values has thus far not accounted for the social labelling of race and ethnicity. Often, determinations are subjective or silently ascribed by a practitioner. Another concern of using reference values is misdiagnosis. This was an important factor in the management and control of compensation for miners in Britain in the interwar period. In this politically loaded context, in which new X-ray technology could not be fully trusted, the spirometer represented secure evidence of respiratory disease in numerical terms that could be used in the complex compensation network.