title: Cancer Incidence in HIV-Infected Versus Uninfected Veterans: Comparison of Cancer Registry and ICD-9 Code Diagnoses.
abstract: BACKGROUND
  Given the growing interest in the cancer burden in persons living with HIV/AIDS, we examined the validity of data sources for cancer diagnoses (cancer registry versus International Classification of Diseases, Ninth Revision [ICD-9 codes]) and compared the association between HIV status and cancer risk using each data source in the Veterans Aging Cohort Study (VACS), a prospective cohort of HIV-infected and uninfected veterans from 1996 to 2008.
  
  
  METHODS
  We reviewed charts to confirm potential incident cancers at four VACS sites. In the entire cohort, we calculated cancer-type-specific age-, sex-, race/ethnicity-, and calendar-period-standardized incidence rates and incidence rate ratios (IRR) (HIV-infected versus uninfected). We calculated standardized incidence ratios (SIR) to compare VACS and Surveillance, Epidemiology, and End Results rates.
  
  
  RESULTS
  Compared to chart review, both Veterans Affairs Central Cancer Registry (VACCR) and ICD-9 diagnoses had approximately 90% sensitivity; however, VACCR had higher positive predictive value (96% versus 63%). There were 6,010 VACCR and 13,386 ICD-9 incident cancers among 116,072 veterans. Although ICD-9 rates tended to be double VACCR rates, most IRRs were in the same direction and of similar magnitude, regardless of data source. Using either source, all cancers combined, most viral-infection-related cancers, lung cancer, melanoma, and leukemia had significantly elevated IRRs. Using ICD-9, eight additional IRRs were significantly elevated, most likely due to false positive diagnoses. Most ICD-9 SIRs were significantly elevated and all were higher than the corresponding VACCR SIR.
  
  
  CONCLUSIONS
  ICD-9 may be used with caution for estimating IRRs, but should be avoided when estimating incidence or SIRs. Elevated cancer risk based on VACCR diagnoses among HIV-infected veterans was consistent with other studies.
authors.affiliation: Department of Chronic Disease Epidemiology, Yale School of Public Health, New Haven, CT, USA ; Department of Epidemiology and Public Health, Yale School of Medicine, New Haven, CT, USA.
authors.forename: Lesley S
authors.initials: LS
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA ; Department of General Internal Medicine, Veterans Affairs Healthcare System, West Haven, CT, USA.
authors.forename: Janet P
authors.initials: JP
authors.lastname: Tate
authors.affiliation: Infectious Diseases Section, Michael E. DeBakey Veterans Affairs Medical Center, Houston, TX, USA ; Department of Medicine, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Maria C
authors.initials: MC
authors.lastname: Rodriguez-Barradas
authors.affiliation: Medical Specialty Care Service Line, Atlanta Veterans Affairs Medical Center, Atlanta, GA, USA ; Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA.
authors.forename: David
authors.initials: D
authors.lastname: Rimland
authors.affiliation: Department of Medicine, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA ; Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
authors.forename: Matthew Bidwell
authors.initials: MB
authors.lastname: Goetz
authors.affiliation: Section of Infectious Diseases, Washington DC Veterans Affairs Medical Center, Washington, DC, USA ; Department of Medicine, George Washington University School of Medicine and Health Sciences, Washington, DC, USA.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Gibert
authors.affiliation: Department of Medicine, James J. Peters Veterans Affairs Medical Center, Bronx, NY, USA ; Department of Medicine, Icahn School of Medicine, Mt. Sinai, New York, NY, USA.
authors.forename: Sheldon T
authors.initials: ST
authors.lastname: Brown
authors.affiliation: Office of Patient Care Services, Department of Veterans Affairs, Washington, DC, USA ; Hematology-Oncology Service, Durham Veterans Affairs Medical Center, Durham, NC, USA ; Division of Medical Oncology, Duke University Medical Center, Durham, NC, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Kelley
authors.affiliation: Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA ; Department of General Internal Medicine, Veterans Affairs Healthcare System, West Haven, CT, USA.
authors.forename: Amy C
authors.initials: AC
authors.lastname: Justice
authors.affiliation: Department of Chronic Disease Epidemiology, Yale School of Public Health, New Haven, CT, USA ; Department of Epidemiology and Public Health, Yale School of Medicine, New Haven, CT, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Dubrow
keywords: HIV Infections; International Classification of Diseases; Neoplasms; Registries