title: Editorial. Comparison of ICD-9-based, retrospective, and prospective assessments of perioperative complications: assessment of accuracy in reporting.
authors.forename: Cheerag D
authors.initials: CD
authors.lastname: Upadhyaya
authors.forename: Praveen V
authors.initials: PV
authors.lastname: Mumaneni
mesh_terms: D015982:Bias; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D006801:Humans; D015994:Incidence; D038801:International Classification of Diseases / Q000706:statistics & numerical data*; D008485:Medical Audit / Q000706:statistics & numerical data; D011183:Postoperative Complications / Q000175:diagnosis* / Q000453:epidemiology*; D011446:Prospective Studies; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012308:Risk Management / Q000706:statistics & numerical data*; D013122:Spinal Diseases / Q000601:surgery*; D013123:Spinal Fusion / Q000706:statistics & numerical data; D055009:Spondylosis / Q000601:surgery