title: Temporal trends in the systemic inflammatory response syndrome, sepsis, and medical coding of sepsis.
abstract: BACKGROUND
  Recent reports using administrative claims data suggest the incidence of community- and hospital-onset sepsis is increasing. Whether this reflects changing epidemiology, more effective diagnostic methods, or changes in physician documentation and medical coding practices is unclear.
  
  
  METHODS
  We performed a temporal-trend study from 2008 to 2012 using administrative claims data and patient-level clinical data of adult patients admitted to Barnes-Jewish Hospital in St. Louis, Missouri. Temporal-trend and annual percent change were estimated using regression models with autoregressive integrated moving average errors.
  
  
  RESULTS
  We analyzed 62,261 inpatient admissions during the 5-year study period. 'Any SIRS' (i.e., SIRS on a single calendar day during the hospitalization) and 'multi-day SIRS' (i.e., SIRS on 3 or more calendar days), which both use patient-level data, and medical coding for sepsis (i.e., ICD-9-CM discharge diagnosis codes 995.91, 995.92, or 785.52) were present in 35.3 %, 17.3 %, and 3.3 % of admissions, respectively. The incidence of admissions coded for sepsis increased 9.7 % (95 % CI: 6.1, 13.4) per year, while the patient data-defined events of 'any SIRS' decreased by 1.8 % (95 % CI: -3.2, -0.5) and 'multi-day SIRS' did not change significantly over the study period. Clinically-defined sepsis (defined as SIRS plus bacteremia) and severe sepsis (defined as SIRS plus hypotension and bacteremia) decreased at statistically significant rates of 5.7 % (95 % CI: -9.0, -2.4) and 8.6 % (95 % CI: -4.4, -12.6) annually. All-cause mortality, SIRS mortality, and SIRS and clinically-defined sepsis case fatality did not change significantly during the study period. Sepsis mortality, based on ICD-9-CM codes, however, increased by 8.8 % (95 % CI: 1.9, 16.2) annually.
  
  
  CONCLUSIONS
  The incidence of sepsis, defined by ICD-9-CM codes, and sepsis mortality increased steadily without a concomitant increase in SIRS or clinically-defined sepsis. Our results highlight the need to develop strategies to integrate clinical patient-level data with administrative data to draw more accurate conclusions about the epidemiology of sepsis.
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, 660 South Euclid Avenue, Campus Box 8051, St. Louis, MO, 63110, USA. bthomas@dom.wustl.edu.|Department of Medicine, John A. Burns School of Medicine, 651 Ilalo Street, Honolulu, 96813, HI, USA. bthomas@dom.wustl.edu.
authors.forename: Benjamin S
authors.initials: BS
authors.lastname: Thomas
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, 660 South Euclid Avenue, Campus Box 8051, St. Louis, MO, 63110, USA. rjafarza@dom.wustl.edu.
authors.forename: S Reza
authors.initials: SR
authors.lastname: Jafarzadeh
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, 660 South Euclid Avenue, Campus Box 8051, St. Louis, MO, 63110, USA. dwarren@dom.wustl.edu.
authors.forename: David K
authors.initials: DK
authors.lastname: Warren
authors.affiliation: Center for Clinical Excellence, BJC HealthCare, 4901 Forest Park Avenue, St. Louis, 63108, MO, USA. asm2148@bjc.org.
authors.forename: Sandra
authors.initials: S
authors.lastname: McCormick
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, 660 South Euclid Avenue, Campus Box 8051, St. Louis, MO, 63110, USA. vfraser@dom.wustl.edu.
authors.forename: Victoria J
authors.initials: VJ
authors.lastname: Fraser
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, 660 South Euclid Avenue, Campus Box 8051, St. Louis, MO, 63110, USA. jonas.marschall@insel.ch.|Department of Infectious Diseases, Bern University Hospital and University of Bern, Friedbühlstrasse 51, CH-3010, Bern, Switzerland. jonas.marschall@insel.ch.
authors.forename: Jonas
authors.initials: J
authors.lastname: Marschall
mesh_terms: D000328:Adult; D000368:Aged; D059019:Clinical Coding / Q000706:statistics & numerical data*; D005260:Female; D017052:Hospital Mortality; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D038801:International Classification of Diseases; D008297:Male; D008875:Middle Aged; D008923:Missouri / Q000453:epidemiology; D018805:Sepsis / Q000453:epidemiology; D018746:Systemic Inflammatory Response Syndrome / Q000453:epidemiology*; D062606:Tertiary Care Centers