title: Validating the diagnostic code for acne in a tertiary care dermatology centre.
abstract: BACKGROUND
  Administrative databases provide valuable patient data and are used to conduct population-based studies. However, no studies have been conducted to validate the codes for dermatological conditions.
  
  
  OBJECTIVE
  To evaluate the validity of ICD 9 code 706 for acne.
  
  
  METHODS
  This was a retrospective chart review of patients seen in dermatology clinics at Sunnybrook Health Sciences Centre between March 1 and May 31, 2013. The billing code for a clinic visit was compared to the diagnosis documented in the medical chart.
  
  
  RESULTS
  There were 4,248 participants; 201 with an ICD-9 code of acne. This code had a PPV and sensitivity with 95% confidence intervals (CI) of 84.58% (78.67-89.13%) and 86.29% (80.51-90.62%), respectively. The specificity was 99.20% (98.86-99.45%).
  
  
  CONCLUSIONS
  We showed that ICD-9 code 706 can be used to accurately identify patients with acne in a dermatology setting. This information can be applied to future epidemiologic studies.
authors.affiliation: Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, M1-700 Toronto, ON M4N 3M5, Canada University of Toronto, Department of Dermatology, Toronto, ON Canada.
authors.forename: Aiza
authors.initials: A
authors.lastname: Ejaz
authors.affiliation: Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, M1-700 Toronto, ON M4N 3M5, Canada University of Toronto, Department of Dermatology, Toronto, ON Canada.
authors.forename: Viba
authors.initials: V
authors.lastname: Malaiyandi
authors.affiliation: Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, M1-700 Toronto, ON M4N 3M5, Canada University of Toronto, Department of Dermatology, Toronto, ON Canada.
authors.forename: Whan Ben
authors.initials: WB
authors.lastname: Kim
authors.affiliation: Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, M1-700 Toronto, ON M4N 3M5, Canada University of Toronto, Department of Dermatology, Toronto, ON Canada.
authors.forename: Tetyana
authors.initials: T
authors.lastname: Rogalska
authors.affiliation: Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, M1-700 Toronto, ON M4N 3M5, Canada University of Toronto, Department of Dermatology, Toronto, ON Canada.
authors.forename: Raed
authors.initials: R
authors.lastname: Alhusayen
mesh_terms: D000152:Acne Vulgaris / Q000145:classification* / Q000175:diagnosis; D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D016208:Databases, Factual; D003880:Dermatology / Q000592:standards; D005260:Female; D006801:Humans; D038801:International Classification of Diseases / Q000592:standards*; D008297:Male; D009864:Ontario; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D062606:Tertiary Care Centers; D055815:Young Adult
keywords: acne; diagnostic code; validity