title: [Is registration of multiple myeloma in the Norwegian Cancer Registry good enough?].
abstract: BACKGROUND
  The last 15 years several studies have evaluated the quality of the Norwegian Cancer Registry. A pilot study from 1981 showed that the registration quality of non-solid tumours was significantly weaker than that for solid tumours. We wanted to study the registration quality of multiple myeloma in the Norwegian Cancer Registry during the 1990s.
  
  
  METHODS
  In the 1990s, the majority of younger Norwegian patients with multiple myeloma diagnosed in certain time periods were included in clinical studies. 348 patients were included, whereas 440 patients were registered in the Norwegian Cancer Registry during the same time period. We compared the patients included in studies with those in the Registry. When a discrepancy was found the diagnostic data and the registration process were looked into.
  
  
  RESULTS
  Registration of multiple myeloma in the Norwegian Cancer Registry in the 1990s had a completeness of 92.7 % and an accuracy of 92.5 %.
  
  
  CONCLUSIONS
  The quality of multiple myeloma registration in the Norwegian Cancer Registry has improved from the 1970s (the data had a completeness of 77-82%) to the 1990s, but is still not as good as the registration of solid tumours. Increased awareness of this problem at pathological and haematological departments can probably improve the quality of registration further.
authors.affiliation: Diakonhjemmet Høgskole Postboks 184 Vinderen 0319 Oslo. martin.aasbrenn@diakonhjemmet.no
authors.forename: Martin
authors.initials: M
authors.lastname: Aasbrenn
authors.forename: Frøydis
authors.initials: F
authors.lastname: Langmark
authors.forename: Finn
authors.initials: F
authors.lastname: Wisløff
mesh_terms: D000328:Adult; D006801:Humans; D009101:Multiple Myeloma / Q000175:diagnosis / Q000453:epidemiology*; D009664:Norway / Q000453:epidemiology; D011785:Quality Assurance, Health Care; D012042:Registries / Q000592:standards*