title: Evaluation of an ICD-10 algorithm to detect osteonecrosis of the jaw among cancer patients in the Danish National Registry of Patients.
abstract: OBJECTIVE
  This study aimed to validate a predefined algorithm for osteonecrosis of the jaw (ONJ) among cancer patients in the Danish National Registry of Patients and to assess the nature of clinical information recorded in medical charts of ONJ patients.
  
  
  METHODS
  We identified potential ONJ cases recorded in 2005-2010 among cancer patients at the hospital Departments of Oral and Maxillofacial Surgery (DOMS) in three Danish regions, using a set of codes from the International Classification of Diseases, 10th revision (ICD-10). We abstracted DOMS charts of the potential cases, had the ONJ status adjudicated by an expert ONJ adjudication committee (ONJAC), and computed positive predictive values. For patients with ONJAC-confirmed ONJ, we abstracted the charts for information on ONJ clinical course. Sensitivity of the algorithm was computed using a separate sample of 101 known ONJ cases accrued in 2005-2011.
  
  
  RESULTS
  We identified 212 potential ONJ cases, of which 197 (93%) had charts available for abstraction. Eighty-three potential cases were confirmed by ONJAC, with a positive predictive value of 42% (95% confidence interval [CI] 35%-49%). DOMS charts of these 83 cases contained complete information on ONJ clinical course. Information about antiresorptive treatment was recorded for 84% of the patients. Among the 101 known ONJ cases, 74 had at least one prespecified ICD-10 code recorded in the Danish National Registry of Patients within ±90 days of the ONJ diagnosis (sensitivity 73%; 95%CI [64%-81%]).
  
  
  CONCLUSIONS
  The predefined algorithm is not adequate for monitoring ONJ in pharmacovigilance studies. Additional case-finding approaches, coupled with adjudication, are necessary to estimate ONJ incidence accurately.
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Vera
authors.initials: V
authors.lastname: Ehrenstein
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark.|Department of Anesthesiology and Intensive Care Medicine, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Henrik
authors.initials: H
authors.lastname: Gammelager
authors.affiliation: Department of Oral and Maxillofacial Surgery, Rigshospitalet, Copenhagen Ø, Denmark.
authors.forename: Morten
authors.initials: M
authors.lastname: Schiødt
authors.affiliation: Department of Oral and Maxillofacial Surgery, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Sven Erik
authors.initials: SE
authors.lastname: Nørholt
authors.affiliation: Department of Oral and Maxillofacial Surgery, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Bjarne
authors.initials: B
authors.lastname: Neumann-Jensen
authors.affiliation: Department of Oral and Maxillofacial Surgery, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Troels Bille
authors.initials: TB
authors.lastname: Folkmar
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Lars
authors.initials: L
authors.lastname: Pedersen
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Claus
authors.initials: C
authors.lastname: Svaerke
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Henrik Toft
authors.initials: HT
authors.lastname: Sørensen
authors.affiliation: Global Biostatistical Science, Amgen Inc., Thousand Oaks, CA, USA.
authors.forename: Haijun
authors.initials: H
authors.lastname: Ma
authors.affiliation: Center for Observational Research, Amgen Inc., Thousand Oaks, CA, USA.
authors.forename: John
authors.initials: J
authors.lastname: Acquavella
mesh_terms: D000368:Aged; D000465:Algorithms; D059266:Bisphosphonate-Associated Osteonecrosis of the Jaw / Q000175:diagnosis* / Q000453:epidemiology*; D050071:Bone Density Conservation Agents / Q000009:adverse effects*; D003718:Denmark / Q000453:epidemiology; D057286:Electronic Health Records; D005260:Female; D006801:Humans; D038801:International Classification of Diseases / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000175:diagnosis* / Q000453:epidemiology; D017891:Pharmacoepidemiology; D012042:Registries
chemical_list: D050071:Bone Density Conservation Agents
keywords: Denmark; International Classification of Diseases; administrative data; cancer; osteonecrosis of the jaw; pharmacoepidemiology; validation