Four costliest outpatient procedures.
D000556:Ambulatory Surgical Procedures / Q000191:economics*; D006328:Cardiac Catheterization / Q000191:economics; D002387:Cataract Extraction / Q000191:economics; D003113:Colonoscopy / Q000191:economics; D003625:Data Collection; D016099:Endoscopy, Gastrointestinal / Q000191:economics; D005251:Fees, Medical / Q000706:statistics & numerical data*; D006801:Humans; D014481:United States