title: Identifying Vasopressor and Inotrope Use for Health Services Research.
abstract: BACKGROUND
  Identifying vasopressor and inotrope (vasopressor) use from administrative claims data may provide an important resource to study the epidemiology of shock.
  
  
  OBJECTIVE
  Determine accuracy of identifying vasopressor use using International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) coding.
  
  
  METHODS
  Using administrative data enriched with pharmacy billing files (Premier, Inc., Charlotte, NC), we identified two cohorts: adult patients admitted with a diagnosis of sepsis from 2010 to 2013 or pulmonary embolism (PE) from 2008 to 2011. Vasopressor administration was obtained using pharmacy billing files (dopamine, dobutamine, epinephrine, milrinone, norepinephrine, phenylephrine, vasopressin) and compared with ICD-9-CM procedure code for vasopressor administration (00.17). We estimated performance characteristics of the ICD-9-CM code and compared patients' characteristics and mortality rates according to vasopressor identification method.
  
  
  RESULTS
  Using either pharmacy data or the ICD-9-CM procedure code, 29% of 541,144 patients in the sepsis cohort and 5% of 81,588 patients in the PE cohort were identified as receiving a vasopressor. In the sepsis cohort, the ICD-9-CM procedure code had low sensitivity (9.4%; 95% confidence interval, 9.2-9.5), which increased over time. Results were similar in the PE cohort (sensitivity, 5.8%; 95% confidence interval, 5.1-6.6). The ICD-9-CM code exhibited high specificity in the sepsis (99.8%) and PE (100%) cohorts. However, patients identified as receiving vasopressors by ICD-9-CM code had significantly higher unadjusted in-hospital mortality, had more acute organ failures, and were more likely hospitalized in the Northeast and West.
  
  
  CONCLUSIONS
  The ICD-9-CM procedure code for vasopressor administration has low sensitivity and selects for higher severity of illness in studies of shock. Temporal changes in sensitivity would likely make longitudinal shock surveillance using ICD-9-CM inaccurate.
authors.affiliation: 1 Department of Medicine, Boston Medical Center, and.
authors.forename: Ashraf
authors.initials: A
authors.lastname: Fawzy
authors.affiliation: 2 The Pulmonary Center, Division of Pulmonary and Critical Care Medicine, Boston University School of Medicine, Boston, Massachusetts; and.
authors.forename: Mark
authors.initials: M
authors.lastname: Bradford
authors.affiliation: 3 Center for Quality of Care Research and Division of General Internal Medicine, Baystate Medical Center, Springfield, Massachusetts.
authors.forename: Peter K
authors.initials: PK
authors.lastname: Lindenauer
authors.affiliation: 1 Department of Medicine, Boston Medical Center, and.|2 The Pulmonary Center, Division of Pulmonary and Critical Care Medicine, Boston University School of Medicine, Boston, Massachusetts; and.
authors.forename: Allan J
authors.identifier: http://orcid.org/0000-0003-4685-6894
authors.initials: AJ
authors.lastname: Walkey
mesh_terms: D000328:Adult; D059019:Clinical Coding; D015331:Cohort Studies; D016208:Databases, Factual; D005260:Female; D006302:Health Services Research; D017052:Hospital Mortality; D006801:Humans; D038801:International Classification of Diseases; D008297:Male; D008875:Middle Aged; D009657:North Carolina; D011655:Pulmonary Embolism / Q000188:drug therapy*; D012680:Sensitivity and Specificity; D018805:Sepsis / Q000188:drug therapy*; D012769:Shock / Q000209:etiology; D014662:Vasoconstrictor Agents / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D014662:Vasoconstrictor Agents
keywords: international classification of diseases; pulmonary embolism; sepsis; shock; vasoconstrictor agents