By the mid-1930s, U.S. coal miners could no longer tolerate company doctors. They objected to the misuse of preemployment and periodic medical examinations and to many other facets of employer-controlled health benefit plans. The rank-and-file movement for reform received critical assistance from the Bureau of Cooperative Medicine, which conducted an extensive investigation of health services in 157 Appalachian communities. This study not only substantiated the workers' indictment of prevailing conditions but illuminated new deficiencies in the quality and availability of hospital and medical care as well. The miners' union curtailed the undemocratic, exploitative system of company doctors and proprietary hospitals by establishing the United Mine Workers of America Welfare and Retirement Fund in 1946.