title: Positive predictive value of primary inpatient discharge diagnoses of infection among cancer patients in the Danish National Registry of Patients.
abstract: OBJECTIVE
  Pharmacovigilance studies of cancer treatment frequently monitor infections. Predictive values of algorithms identifying disease depend on prevalence of the disease in the population under study. We therefore estimated the positive predictive value (PPV) of primary inpatient diagnosis of infection among cancer patients in the Danish National Registry of Patients (DNRP).
  
  
  METHODS
  The algorithm to identify infections in the DNPR was based on International Classification of Diseases, 10th revision (ICD-10) codes. A physician blinded to the type of sampled infection reviewed the medical charts and assessed the presence and type of infection. Using the physician global assessment as gold standard, we computed PPVs with and without requiring agreement on infection type.
  
  
  RESULTS
  We retrieved 266 of 272 medical charts (98%). Presence of infection was confirmed in 261 patients, resulting in an overall PPV of 98% (95% confidence interval, 96%-99%). When requiring agreement on infection type, overall PPV was 77%. For skin infections, pneumonia, and sepsis, PPVs were 79%, 93% and 84%, respectively. For these infections, we additionally calculated PPVs using evidence-based criteria as the gold standard. PPV was similar for pneumonia, but lower for skin infections and sepsis.
  
  
  CONCLUSIONS
  The Danish National Registry of Patients is suitable for monitoring infections requiring hospitalization among cancer patients.
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark. Electronic address: louise.bill@dce.au.dk.
authors.forename: Louise
authors.initials: L
authors.lastname: Holland-Bill
authors.affiliation: Center for Observational Research, Amgen Inc., Thousand Oaks, CA.
authors.forename: Hairong
authors.initials: H
authors.lastname: Xu
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Henrik Toft
authors.initials: HT
authors.lastname: Sørensen
authors.affiliation: Center for Observational Research, Amgen Inc., Thousand Oaks, CA.
authors.forename: John
authors.initials: J
authors.lastname: Acquavella
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Claus
authors.initials: C
authors.lastname: Sværke
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Epidemiology, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Henrik
authors.initials: H
authors.lastname: Gammelager
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Vera
authors.initials: V
authors.lastname: Ehrenstein
mesh_terms: D000368:Aged; D000465:Algorithms; D000970:Antineoplastic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D015897:Comorbidity; D003718:Denmark / Q000453:epidemiology; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007239:Infections / Q000139:chemically induced* / Q000453:epidemiology / Q000209:etiology; D007297:Inpatients / Q000706:statistics & numerical data*; D038801:International Classification of Diseases; D008297:Male; D008498:Medical Record Linkage; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications / Q000188:drug therapy* / Q000453:epidemiology; D010351:Patient Discharge / Q000706:statistics & numerical data*; D060735:Pharmacovigilance; D011237:Predictive Value of Tests; D012042:Registries
chemical_list: D000970:Antineoplastic Agents
keywords: Cancer; Infection; International Classification of Disease codes; Pharmacoepidemiology; Predictive value of tests