title: ASA grade and Charlson Comorbidity Index of spinal surgery patients: correlation with complications and societal costs.
abstract: BACKGROUND
  The Charlson Comorbidity Index (CCI) and the American Society of Anesthesiologists (ASA) Physical Status Classification System (ASA grade) are useful for predicting morbidity and mortality for a variety of disease processes.
  
  
  OBJECTIVE
  To evaluate CCI and ASA grade as predictors of complications after spinal surgery and examine the correlation between these comorbidity indices and the cost of care.
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  All patients undergoing any spine surgery at a single academic tertiary center over a 6-month period.
  
  
  METHODS
  Direct health-care costs estimated from diagnosis related group and Current Procedural Terminology (CPT) codes.
  
  
  METHODS
  Demographic data, including all patient comorbidities, procedural data, and all complications, occurring within 30 days of the index procedure were prospectively recorded. Charlson Comorbidity Index was calculated from International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes and ASA grades determined from the operative record. Diagnosis related group and CPT codes were captured for each patient. Direct costs were estimated from a societal perspective using Medicare rates of reimbursement. A multivariable analysis was performed to assess the association of the CCI and ASA grade to the rate of complication and direct health-care costs.
  
  
  RESULTS
  Two hundred twenty-six cases were analyzed. The average CCI score for the patient cohort was 0.92, and the average ASA grade was 2.65. The CCI and ASA grade were significantly correlated, with Spearman ρ of 0.458 (p<.001). Both CCI and ASA grade were associated with increasing body mass index (p<.01) and increasing patient age (p<.0001). Increasing CCI was associated with an increasing likelihood of occurrence of any complication (p=.0093) and of minor complications (p=.0032). Increasing ASA grade was significantly associated with an increasing likelihood of occurrence of a major complication (p=.0035). Increasing ASA grade showed a significant association with increasing direct costs (p=.0062).
  
  
  CONCLUSIONS
  American Society of Anesthesiologists and CCI scores are useful comorbidity indices for the spine patient population, although neither was completely predictive of complication occurrence. A spine-specific comorbidity index, based on ICD-9-CM coding that could be easily captured from patient records, and which is predictive of patient likelihood of complications and mortality, would be beneficial in patient counseling and choice of operative intervention.
authors.affiliation: Department of Neurosurgery, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Whitmore
authors.affiliation: Department of Neurosurgery, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA.
authors.forename: James H
authors.initials: JH
authors.lastname: Stephen
authors.affiliation: Department of Anesthesiology, Thomas Jefferson University, 3400 Spruce Street, Philadelphia, PA 19107, USA.
authors.forename: Coleen
authors.initials: C
authors.lastname: Vernick
authors.affiliation: Department of Neurosurgery, Thomas Jefferson University, 111 S 11th Street, Philadelphia, PA 19107, USA.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Campbell
authors.affiliation: Department of Neurosurgery, Thomas Jefferson University, 111 S 11th Street, Philadelphia, PA 19107, USA.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Yadla
authors.affiliation: Department of Neurosurgery, Thomas Jefferson University, 111 S 11th Street, Philadelphia, PA 19107, USA.
authors.forename: George M
authors.initials: GM
authors.lastname: Ghobrial
authors.affiliation: Department of Neurosurgery, Thomas Jefferson University, 111 S 11th Street, Philadelphia, PA 19107, USA.
authors.forename: Mitchell G
authors.initials: MG
authors.lastname: Maltenfort
authors.affiliation: Department of Neurosurgery, Thomas Jefferson University, 111 S 11th Street, Philadelphia, PA 19107, USA. Electronic address: john.ratliff@jefferson.edu.
authors.forename: John K
authors.initials: JK
authors.lastname: Ratliff
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D017281:Cost of Illness; D005260:Female; D017048:Health Care Costs; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000009:adverse effects* / Q000191:economics; D011183:Postoperative Complications / Q000191:economics / Q000453:epidemiology*; D011446:Prospective Studies; D013122:Spinal Diseases / Q000191:economics / Q000453:epidemiology / Q000601:surgery*; D013131:Spine / Q000601:surgery*
keywords: American Society of Anesthesiologists grade; Charlson Comorbidity Index; Complications; Societal costs; Spinal surgery