title: Validation of CKD and related conditions in existing data sets: A systematic review.
abstract: BACKGROUND
  Accurate classification of individuals with kidney disease is vital to research and public health efforts aimed at improving health outcomes. Our objective is to identify and synthesize published literature evaluating the accuracy of existing data sources related to kidney disease.
  
  
  METHODS
  A systematic review of studies seeking to validate the accuracy of the underlying data relevant to kidney disease.
  
  
  METHODS
  US-based and international studies covering a wide range of both outpatient and inpatient study populations.
  
  
  METHODS
  Any English-language study investigating the prevalence or cause of kidney disease, existence of comorbid conditions, or cause of death in patients with chronic kidney disease (CKD). All definitions and stages of CKD, including end-stage renal disease (ESRD), were accepted.
  
  
  METHODS
  Presence of a kidney disease-related variable in existing data sets, including administrative data sets and disease registries.
  
  
  METHODS
  Presence of a kidney disease-related variable defined using laboratory criteria or medical record review.
  
  
  RESULTS
  30 studies were identified. Most studies investigated the accuracy of kidney disease reporting, comparing coded renal disease with that defined using estimated glomerular filtration rate. The sensitivity of coded renal disease varied widely (0.08-0.83). Specificity was higher, with all studies reporting values ≥0.90. Studies evaluating the cause of CKD, comorbid conditions, and cause of death in patients with CKD used ESRD or transplant populations exclusively, and accuracy was highly variable compared with ESRD registry data.
  
  
  CONCLUSIONS
  Only English-language studies were evaluated.
  
  
  CONCLUSIONS
  Given the heterogeneous results of validation studies, a variety of attributes of existing data sources, including the accuracy of individual data items within these sources, should be considered carefully before use in research, quality improvement, and public health efforts.
authors.affiliation: Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA.
authors.forename: Morgan E
authors.initials: ME
authors.lastname: Grams
authors.forename: Laura C
authors.initials: LC
authors.lastname: Plantinga
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Hedgeman
authors.forename: Rajiv
authors.initials: R
authors.lastname: Saran
authors.forename: Gary L
authors.initials: GL
authors.lastname: Myers
authors.forename: Desmond E
authors.initials: DE
authors.lastname: Williams
authors.forename: Neil R
authors.initials: NR
authors.lastname: Powe
mesh_terms: D002423:Cause of Death; D016208:Databases, Factual; D005919:Glomerular Filtration Rate; D006801:Humans; D051436:Renal Insufficiency, Chronic / Q000145:classification* / Q000150:complications / Q000175:diagnosis / Q000401:mortality; D016019:Survival Analysis