title: Letter: Explicit criteria for use of laboratory tests.
mesh_terms: D019411:Clinical Laboratory Techniques; D004077:Digoxin / Q000008:administration & dosage / Q000097:blood* / Q000627:therapeutic use; D006333:Heart Failure / Q000188:drug therapy*; D006801:Humans; D012189:Retrospective Studies; D014600:Utilization Review
chemical_list: D004077:Digoxin