Opioid Abuse or Dependence Increases 30-day Readmission Rates after Major Operating Room Procedures: A National Readmissions Database Study. - Gupta A; Nizamuddin J; Elmofty D; Nizamuddin SL; Tung A; Minhaj M; Mueller A; Apfelbaum J; Shahul S (Anesthesiology, 2018)