title: Validation of the V66.7 Code for Palliative Care Consultation in a Single Academic Medical Center.
abstract: Use of administrative data to study the effectiveness of specialized palliative care is limited by the lack of a reliable method to identify patients receiving palliative care consultation. The International Classification of Diseases, Ninth Revision (ICD-9) code V66.7 has been used, but its validity for this purpose is unknown.
  
  
  
  To examine the validity of the ICD-9 code V66.7 for identifying whether hospitalized patients received palliative care consultation.
  
  
  
  Retrospective cohort study.
  
  
  
  All patients of age ≥18 years admitted to a single academic medical center between August 2013 and August 2015.
  
  
  
  Sensitivity and specificity of the V66.7 code for palliative care consultation for all patients and several a priori identified subgroups. The reference standard was the presence of a palliative care consultation note in the electronic medical record.
  
  
  
  Of 100,910 admissions, 1999 received a palliative care consultation (2.0%) and 1846 (1.8%) had usage of the V66.7 code. Sensitivity and specificity for the V66.7 code were 49.9% and 99.1%, respectively. Sensitivity was considerably higher for certain subgroups, such as patients with dementia (76.3%) and metastatic cancer (66.3%); addition of age restrictions further improved sensitivity while maintaining high specificity. Specificity was substantially lower for patients who died during hospitalization (sensitivity 53.9%, specificity 75.1%).
  
  
  
  In a single center, the ICD-9 code V66.7 had poor sensitivity and high specificity for identifying hospitalized patients who received a palliative care consultation. Appropriate use of this code for this purpose should take these characteristics into consideration.
authors.affiliation: 1 Department of Anesthesiology, Columbia University , New York, New York.|2 Department of Epidemiology, Columbia University Mailman School of Public Health , New York, New York.
authors.forename: May
authors.initials: M
authors.lastname: Hua
authors.affiliation: 2 Department of Epidemiology, Columbia University Mailman School of Public Health , New York, New York.|3 Department of Anesthesiology, Center for Health Policy and Outcomes in Anesthesia and Critical Care, Columbia University College of Physicians and Surgeons .
authors.forename: Guohua
authors.initials: G
authors.lastname: Li
authors.affiliation: 1 Department of Anesthesiology, Columbia University , New York, New York.
authors.forename: Caitlin
authors.initials: C
authors.lastname: Clancy
authors.affiliation: 4 Brookdale Department of Geriatrics and Palliative Medicine, Icahn School of Medicine at Mount Sinai , New York, New York.
authors.forename: R Sean
authors.initials: RS
authors.lastname: Morrison
authors.affiliation: 1 Department of Anesthesiology, Columbia University , New York, New York.|5 Department of Critical Care Medicine, Sunnybrook Health Sciences Centre , Toronto, Ontario, Canada .|6 Department of Anesthesia, University of Toronto , Toronto, Ontario, Canada .
authors.forename: Hannah
authors.initials: H
authors.lastname: Wunsch
mesh_terms: D000046:Academic Medical Centers; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059019:Clinical Coding; D057286:Electronic Health Records / Q000592:standards* / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007297:Inpatients / Q000145:classification* / Q000706:statistics & numerical data; D038801:International Classification of Diseases; D008297:Male; D008875:Middle Aged; D010166:Palliative Care / Q000145:classification* / Q000706:statistics & numerical data; D012017:Referral and Consultation / Q000145:classification* / Q000706:statistics & numerical data; D012189:Retrospective Studies; D055815:Young Adult
keywords: International Classification of Disease Codes; end-of-life care; palliative medicine; validation studies