title: Validity of major osteoporotic fracture diagnosis codes in the Clinical Data Analysis and Reporting System in Hong Kong.
abstract: OBJECTIVE
  Large medical record databases facilitate epidemiology research in fracture. However, the validity of fracture in the databases is needed to ensure the reliability of data. We aimed to assess the validity of International Classification of Diseases, 9th Revision (ICD-9) code algorithms for identifying major osteoporotic fracture in the Clinical Data Analysis and Reporting System (CDARS) in Hong Kong.
  
  
  METHODS
  The CDARS is a database developed by the Hong Kong Hospital Authority for research purpose. We used ICD-9 code algorithm for identifying major osteoporotic fracture, including vertebral fracture, humerus fracture, forearm/wrist fracture, and hip fracture, in CDARS in 2005-2016. As high positive predictive value (PPV) is critically important in epidemiology research, we sought to determine the PPV of fracture diagnostic code in terms of ICD-9 relative to the radiography imaging and clinical notes. A total of 380 major osteoporotic fracture cases (vertebral fracture: 101 cases; humerus fracture: 81 cases; forearm/wrist fracture: 94 cases; and hip fracture: 104 cases) were randomly selected and validated.
  
  
  RESULTS
  In 380 fracture cases, the overall PPV was 96.8%. In subgroup analysis, PPV of 100% was observed for hip, humerus, and forearm/wrist fractures, whereas PPV of 86% was observed for vertebral fracture.
  
  
  CONCLUSIONS
  The use of ICD-9 code algorithm to identify major osteoporotic fracture in CDARS is a valid tool with a very high PPV. However, cautious interpretation is required when the study focuses on incident vertebral fracture. Copyright © 2017 John Wiley & Sons, Ltd.
authors.affiliation: Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong.
authors.forename: Chor-Wing
authors.identifier: http://orcid.org/0000-0002-2180-3676
authors.initials: CW
authors.lastname: Sing
authors.affiliation: Department of Medicine, Queen Mary Hospital, Pokfulam, Hong Kong.
authors.forename: Yu-Cho
authors.initials: YC
authors.lastname: Woo
authors.affiliation: Department of Medicine, Queen Mary Hospital, Pokfulam, Hong Kong.
authors.forename: Alan C H
authors.initials: ACH
authors.lastname: Lee
authors.affiliation: Department of Medicine, Queen Mary Hospital, Pokfulam, Hong Kong.
authors.forename: Joanne K Y
authors.initials: JKY
authors.lastname: Lam
authors.affiliation: Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong.
authors.forename: Jody K P
authors.initials: JKP
authors.lastname: Chu
authors.affiliation: Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong.|Research Department of Practice and Policy, UCL School of Pharmacy, London, UK.
authors.forename: Ian C K
authors.initials: ICK
authors.lastname: Wong
authors.affiliation: Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong.|The State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong.|Centre for Genomic Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong.
authors.forename: Ching-Lung
authors.initials: CL
authors.lastname: Cheung
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016208:Databases, Factual / Q000592:standards* / Q000706:statistics & numerical data; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006784:Hospitals, Teaching / Q000592:standards / Q000706:statistics & numerical data; D006801:Humans; D038801:International Classification of Diseases / Q000592:standards* / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D058866:Osteoporotic Fractures / Q000175:diagnosis* / Q000453:epidemiology*; D013223:Statistics as Topic / Q000592:standards*
keywords: ICD-9; fracture; osteoporosis; pharmacoepidemiology; positive predictive value