APCs and observation: learn when to admit.
D000553:Ambulatory Care / Q000145:classification* / Q000191:economics; D004636:Emergency Service, Hospital / Q000191:economics*; D006801:Humans; D007362:Intensive Care Units / Q000191:economics*; D019370:Observation; D010343:Patient Admission; D011445:Prospective Payment System; D014481:United States