title: Technical evaluation of methods for identifying chemotherapy-induced febrile neutropenia in healthcare claims databases.
abstract: BACKGROUND
  Healthcare claims databases have been used in several studies to characterize the risk and burden of chemotherapy-induced febrile neutropenia (FN) and effectiveness of colony-stimulating factors against FN. The accuracy of methods previously used to identify FN in such databases has not been formally evaluated.
  
  
  METHODS
  Data comprised linked electronic medical records from Geisinger Health System and healthcare claims data from Geisinger Health Plan. Subjects were classified into subgroups based on whether or not they were hospitalized for FN per the presumptive "gold standard" (ANC <1.0×10(9)/L, and body temperature ≥38.3°C or receipt of antibiotics) and claims-based definition (diagnosis codes for neutropenia, fever, and/or infection). Accuracy was evaluated principally based on positive predictive value (PPV) and sensitivity.
  
  
  RESULTS
  Among 357 study subjects, 82 (23%) met the gold standard for hospitalized FN. For the claims-based definition including diagnosis codes for neutropenia plus fever in any position (n=28), PPV was 100% and sensitivity was 34% (95% CI: 24-45). For the definition including neutropenia in the primary position (n=54), PPV was 87% (78-95) and sensitivity was 57% (46-68). For the definition including neutropenia in any position (n=71), PPV was 77% (68-87) and sensitivity was 67% (56-77).
  
  
  CONCLUSIONS
  Patients hospitalized for chemotherapy-induced FN can be identified in healthcare claims databases--with an acceptable level of mis-classification--using diagnosis codes for neutropenia, or neutropenia plus fever.
authors: Policy Analysis Inc., Brookline, MA, USA. dweycker@pai2.com
authors: Derek
authors: D
authors: Weycker
authors: Oleg
authors: O
authors: Sofrygin
authors: Kim
authors: K
authors: Seefeld
authors: Robert G
authors: RG
authors: Deeter
authors: Jason
authors: J
authors: Legg
authors: John
authors: J
authors: Edelsberg
mesh_terms: D000368:Aged; D000970:Antineoplastic Agents / Q000009:adverse effects*; D003115:Colony-Stimulating Factors / Q000627:therapeutic use; D016001:Confidence Intervals; D016208:Databases, Factual; D005260:Female; D005334:Fever / Q000139:chemically induced* / Q000145:classification*; D006801:Humans; D007345:Insurance Claim Review; D008297:Male; D008875:Middle Aged; D009503:Neutropenia / Q000139:chemically induced* / Q000145:classification*; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity
chemical_list: D000970:Antineoplastic Agents; D003115:Colony-Stimulating Factors