title: Comparison of trends in sepsis incidence and coding using administrative claims versus objective clinical data.
abstract: BACKGROUND
  National reports of a dramatic rise in sepsis incidence are largely based on analyses of administrative databases. It is unclear if these estimates are biased by changes in coding practices over time.
  
  
  METHODS
  We calculated linear trends in the annual incidence of septicemia, sepsis, and severe sepsis at 2 academic hospitals from 2003 to 2012 using 5 different claims methods and compared case identification rates to selected objective clinical markers, including positive blood cultures, vasopressors, and/or lactic acid levels.
  
  
  RESULTS
  The annual incidence of hospitalizations with sepsis claims increased over the decade, ranging from a 54% increase for the method combining septicemia, bacteremia, and fungemia codes (P < .001 for linear trend) to a 706% increase for explicit severe sepsis/septic shock codes (P = .001). In contrast, the incidence of hospitalizations with positive blood cultures decreased by 17% (P = .006), and hospitalizations with positive blood cultures with concurrent vasopressors and/or lactic acidosis remained stable (P = .098). The sensitivity of sepsis claims for capturing hospitalizations with positive blood cultures with concurrent vasopressors and/or lactic acidosis increased (P < .001 for all methods), whereas the proportion of septicemia hospitalizations with positive blood cultures decreased from 50% to 30% (P < .001).
  
  
  CONCLUSIONS
  The incidence of hospitalizations with sepsis codes rose dramatically while hospitalizations with corresponding objective clinical markers remained stable or decreased. Coding for sepsis has become more inclusive, and septicemia diagnoses are increasingly being applied to patients without positive blood cultures. These changes likely explain some of the apparent rise in sepsis incidence and underscore the need for more reliable surveillance methods.
authors.affiliation: Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Chanu
authors.initials: C
authors.lastname: Rhee
authors.affiliation: Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute.
authors.forename: Michael V
authors.initials: MV
authors.lastname: Murphy
authors.affiliation: Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute.
authors.forename: Lingling
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute.
authors.forename: Richard
authors.initials: R
authors.lastname: Platt
authors.affiliation: Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Michael
authors.initials: M
authors.lastname: Klompas
mesh_terms: D000368:Aged; D015331:Cohort Studies; D003625:Data Collection / Q000379:methods*; D004812:Epidemiologic Methods; D005260:Female; D006785:Hospitals, University; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D018805:Sepsis / Q000453:epidemiology*
keywords: administrative coding; bloodstream infections; incidence; sepsis; septicemia