title: Developing an Algorithm to Identify History of Cancer Using Electronic Medical Records.
abstract: OBJECTIVE
  The objective of this study was to develop an algorithm to identify Kaiser Permanente Colorado (KPCO) members with a history of cancer.
  
  
  BACKGROUND
  Tumor registries are used with high precision to identify incident cancer, but are not designed to capture prevalent cancer within a population. We sought to identify a cohort of adults with no history of cancer, and thus, we could not rely solely on the tumor registry.
  
  
  METHODS
  We included all KPCO members between the ages of 40-75 years who were continuously enrolled during 2013 (N=201,787). Data from the tumor registry, chemotherapy files, inpatient and outpatient claims were used to create an algorithm to identify members with a high likelihood of cancer. We validated the algorithm using chart review and calculated sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for occurrence of cancer.
  
  
  RESULTS
  The final version of the algorithm achieved a sensitivity of 100 percent and specificity of 84.6 percent for identifying cancer. If we relied on the tumor registry alone, 47 percent of those with a history of cancer would have been missed.
  
  
  CONCLUSIONS
  Using the tumor registry alone to identify a cohort of patients with prior cancer is not sufficient. In the final version of the algorithm, the sensitivity and PPV were improved when a diagnosis code for cancer was required to accompany oncology visits or chemotherapy administration.
  
  
  CONCLUSIONS
  Electronic medical record (EMR) data can be used effectively in combination with data from the tumor registry to identify health plan members with a history of cancer.
authors.affiliation: Kaiser Permanente Institute for Health Research.
authors.forename: Christina L
authors.initials: CL
authors.lastname: Clarke
authors.affiliation: Kaiser Permanente Institute for Health Research.
authors.forename: Heather S
authors.initials: HS
authors.lastname: Feigelson
keywords: algorithm; cancer; electronic health record