title: Validation of diagnosis of aplastic anaemia in La Rioja (Spain) by International Classification of Diseases codes for case ascertainment for the Spanish National Rare Diseases Registry.
abstract: OBJECTIVE
  To analyse the validity of diagnosis of aplastic anaemia (AA) by International Classification of Diseases codes in hospital discharge data (MBDS) and the mortality registry (MR) of La Rioja to detect cases to be included in the Spanish National Rare Diseases Registry.
  
  
  METHODS
  International Classification of Diseases (ICD) codes were used to detect AA cases during the period 2007-2012 from two administrative databases: the MBDS and the MR of La Rioja (Spain). Medical records of population selected by merging both databases were used to confirm true AA cases. The annual mean incidence rate of AA was calculated using confirmed incident cases.
  
  
  RESULTS
  By merging both databases, 62 hypothetical AA incident patients were detected during the period 2007-2012. The medical records of the 89% of them could be revised, and they confirmed that only the 15% of the patients actually suffered AA. The annual mean AA incidence in La Rioja was 4.17 per million inhabitants (6.23 per million, males; 2.10 per million, females).
  
  
  CONCLUSIONS
  The MBDS and the MR are not in themselves sufficient to ascertain AA cases in La Rioja and medical records should be reviewed to confirm true AA cases to be included in the Spanish National Rare Diseases Registry.
authors.affiliation: Department of Epidemiology, (SpainRDR Project) La Rioja Regional Authority, La Rioja, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Ruiz
authors.forename: Enrique
authors.initials: E
authors.lastname: Ramalle-Gómara
authors.forename: Carmen
authors.initials: C
authors.lastname: Quiñones
authors.forename: Pilar
authors.initials: P
authors.lastname: Rabasa
authors.forename: Carlos
authors.initials: C
authors.lastname: Pisón
mesh_terms: D000741:Anemia, Aplastic / Q000175:diagnosis* / Q000453:epidemiology / Q000401:mortality / Q000473:pathology; D016208:Databases, Factual / Q000706:statistics & numerical data; D003951:Diagnostic Errors / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D015994:Incidence; D038801:International Classification of Diseases; D008297:Male; D010351:Patient Discharge / Q000706:statistics & numerical data; D012042:Registries / Q000706:statistics & numerical data*; D013030:Spain / Q000453:epidemiology; D016019:Survival Analysis; D009626:Terminology as Topic
keywords: ICD; administrative database; rare disease; surveillance