Variations in medical practice: implications for health policy.
D002391:Catchment Area, Health; D003953:Diagnosis-Related Groups; D005102:Health Expenditures; D006291:Health Policy; D006296:Health Services / Q000706:statistics & numerical data*; D006300:Health Services Misuse; D006801:Humans; D011445:Prospective Payment System; D014481:United States