Ambulatory care and the poor: tracking the impact of changes in federal policy.
D000553:Ambulatory Care / Q000706:statistics & numerical data*; D006262:Health; D006291:Health Policy; D006297:Health Services Accessibility; D006304:Health Status; D006801:Humans; D007182:Income; D007348:Insurance, Health; D008484:Medicaid; D011203:Poverty; D011315:Preventive Medicine; D013997:Time Factors; D014481:United States