title: Missing laboratory results data in electronic health databases: implications for monitoring diabetes risk.
abstract: OBJECTIVE
  Laboratory test (lab) results may be useful to detect incident diabetes in electronic health record and claims-based studies.
  
  
  METHODS
  Using the Mini-Sentinel distributed database, we assessed the value of lab results added to diagnosis codes and dispensing claims to identify incident diabetes.
  
  
  RESULTS
  Inclusion of lab results increased the number of diabetes outcomes identified by 21%. In settings where capture of lab results was relatively complete, the absence of lab results was associated with implausibly low rates of the outcome.
  
  
  CONCLUSIONS
  Lab results can increase sensitivity of algorithms for detecting diabetes, and missing lab results are associated with much lower rates of diabetes ascertainment regardless of algorithm. Patterns of missing lab results may identify ascertainment bias.
authors.affiliation: Weill Cornell Medicine, NY, USA.
authors.forename: James H
authors.initials: JH
authors.lastname: Flory
authors.affiliation: University of Pennsylvania, Philadelphia, PA, 9103, USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Roy
authors.affiliation: Brigham & Women's Hospital, Boston, MA, 02115, USA.
authors.forename: Joshua J
authors.initials: JJ
authors.lastname: Gagne
authors.affiliation: HealthCore Inc, Wilmingon, DE, 19801, USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: Haynes
authors.affiliation: Kaiser Permanente, Oakland, CA, 94612, USA.
authors.forename: Lisa
authors.initials: L
authors.lastname: Herrinton
authors.affiliation: Harvard Pilgrim, Boston, MA, 02215, USA.
authors.forename: Christine
authors.initials: C
authors.lastname: Lu
authors.affiliation: Partner's Healthcare System, Boston, MA, 02215, USA.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Patorno
authors.affiliation: US FDA, Silver Spring, MD, 20993, USA.
authors.forename: Azadeh
authors.initials: A
authors.lastname: Shoaibi
authors.affiliation: Kaiser Permanente, Oakland, CA, 94612, USA.
authors.forename: Marsha A
authors.initials: MA
authors.lastname: Raebel
mesh_terms: D019411:Clinical Laboratory Techniques; D016208:Databases, Factual; D003920:Diabetes Mellitus / Q000175:diagnosis*; D057286:Electronic Health Records / Q000706:statistics & numerical data*; D006801:Humans; D012306:Risk
keywords: ascertainment bias; cohort studies; endocrinology; metabolism