title: Validity of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) screening for sepsis in surgical mortalities.
abstract: BACKGROUND
  Sepsis is among the leading causes of death in the United States. The Agency for Healthcare Research and Quality uses International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) billing code screening for the identification of sepsis. We investigated the incidence of sepsis in mortality at our academic medical center through ICD-9-CM screening of billing codes corresponding to sepsis and compared this approach for accuracy using physician chart review as the gold-standard.
  
  
  METHODS
  Two hundred forty-three surgical mortalities between January 2012 and January 2013 were reviewed by a Performance Improvement team. All mortalities were screened and evaluated for sepsis using physician chart review and ICD-9-CM codes for sepsis (995.91), severe sepsis (995.92), and septic shock (785.52).
  
  
  RESULTS
  Unexpected mortalities were associated with higher rates of sepsis and expected mortalities than anticipated (p<0.0001). A total of 40.6% of patients with sepsis suffered from more than one infection; the most common infectious sources were intra-abdominal (43.5%), blood stream (40.3%), and pulmonary (38.7%) infections. Screening by ICD-9-CM identified sepsis in 23.0% of mortalities, and physician review identified sepsis in 25.5% of mortalities. The sensitivity and specificity of ICD-9-CM screening were 82.3% and 78.3%, respectively. The positive and negative predictive values were 91.1% and 62.1%, respectively.
  
  
  CONCLUSIONS
  Sepsis is a common concurrent condition in surgical patients who die unexpectedly. Screening by ICD-9-CM for sepsis is accurate in identifying patients with sepsis but misses the identification of all patients with sepsis. The diagnostic accuracy of ICD-9-CM screening for sepsis is currently not adequate for public reporting or benchmarking, and is useful only as a guide for institutional quality improvement.
authors.affiliation: 1 Department of Surgery, VCU Medical Center , Richmond, Virginia.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Ramanathan
authors.forename: Patricia
authors.initials: P
authors.lastname: Leavell
authors.forename: Gregory
authors.initials: G
authors.lastname: Stockslager
authors.forename: Catherine
authors.initials: C
authors.lastname: Mays
authors.forename: Dale
authors.initials: D
authors.lastname: Harvey
authors.forename: Therese M
authors.initials: TM
authors.lastname: Duane
mesh_terms: D000328:Adult; D006801:Humans; D038801:International Classification of Diseases / Q000592:standards*; D011183:Postoperative Complications / Q000175:diagnosis / Q000401:mortality; D012680:Sensitivity and Specificity; D018805:Sepsis / Q000145:classification* / Q000175:diagnosis / Q000401:mortality; D013514:Surgical Procedures, Operative / Q000009:adverse effects