title: The development and use of freestanding emergency centers: a review of the literature.
mesh_terms: D003625:Data Collection; D004465:Economic Competition; D004632:Emergency Medical Services / Q000706:statistics & numerical data / Q000600:supply & distribution*; D005069:Evaluation Studies as Topic; D006297:Health Services Accessibility; D010067:Ownership; D010342:Patient Acceptance of Health Care; D012959:Socioeconomic Factors; D014481:United States