title: Alignment of systematic reviews published in the Cochrane Database of Systematic Reviews and the Database of Abstracts and Reviews of Effectiveness with global burden-of-disease data: a bibliographic analysis.
abstract: BACKGROUND
  Systematic reviews of high-quality evidence are used to inform policy and practice. To improve community health, the production of such reviews should align with burden of disease. This study aims to assess if the volume of research output from systematic reviews proportionally aligns with burden of disease assessed using percentages of mortality and disability-adjusted life years (DALYs).
  
  
  METHODS
  A cross-sectional audit of reviews published between January 2012 and August 2013 in the Cochrane Database of Systematic Reviews (CDSR) and Database of Abstracts of Reviews of Effects (DARE) was undertaken. Percentages of mortality and DALYs were obtained from the 2010 Global Burden of Disease study. Standardised residual differences (SRD) based on percentages of mortality and DALYs were calculated, where conditions with SRD of more than or less than three were considered overstudied or understudied, respectively.
  
  
  RESULTS
  1029 reviews from CDSR and 1928 reviews from DARE were examined. There was a significant correlation between percentage DALYs and systematic reviews published in CDSR and DARE databases (CDSR: r=0.68, p=0.001; DARE: r=0.60, p<0.001). There was no significant correlation between percentage mortality and number of systematic reviews published in either database (CDSR: r=0.34, p=0.14; DARE: r=0.22, p=0.34). Relative to percentage of mortality, mental and behavioural disorders, musculoskeletal conditions and other non-communicable diseases were overstudied. Maternal disorders were overstudied relative to percentages of mortality and DALYs in CDSR.
  
  
  CONCLUSIONS
  The focus of systematic reviews is moderately correlated with DALYs. A number of conditions may be overstudied relative to percentage of mortality particularly in the context of health and medical reviews.
authors.affiliation: Hunter New England Population Health, Wallsend, New South Wales, Australia The University of Newcastle, School of Medicine and Public Health, Callaghan, New South Wales, Australia Hunter Medical Research Institute, New Lambton, New South Wales, Australia.
authors.forename: Sze Lin
authors.initials: SL
authors.lastname: Yoong
authors.affiliation: The University of Newcastle, School of Medicine and Public Health, Callaghan, New South Wales, Australia Hunter Medical Research Institute, New Lambton, New South Wales, Australia.
authors.forename: Alix
authors.initials: A
authors.lastname: Hall
authors.affiliation: Hunter New England Population Health, Wallsend, New South Wales, Australia The University of Newcastle, School of Medicine and Public Health, Callaghan, New South Wales, Australia Hunter Medical Research Institute, New Lambton, New South Wales, Australia The George Institute for Global Health, Sydney, New South Wales, Australia.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Williams
authors.affiliation: The University of Newcastle, School of Medicine and Public Health, Callaghan, New South Wales, Australia.
authors.forename: Eliza
authors.initials: E
authors.lastname: Skelton
authors.affiliation: The University of Newcastle, School of Medicine and Public Health, Callaghan, New South Wales, Australia Hunter Medical Research Institute, New Lambton, New South Wales, Australia.
authors.forename: Christopher
authors.initials: C
authors.lastname: Oldmeadow
authors.affiliation: Hunter New England Population Health, Wallsend, New South Wales, Australia The University of Newcastle, School of Medicine and Public Health, Callaghan, New South Wales, Australia Hunter Medical Research Institute, New Lambton, New South Wales, Australia.
authors.forename: John
authors.initials: J
authors.lastname: Wiggers
authors.affiliation: Columbia University College of Physicians and Surgeons, New York, New York, USA.
authors.forename: Chante
authors.initials: C
authors.lastname: Karimkhani
authors.affiliation: Georgetown University School of Medicine, Washington DC, USA.
authors.forename: Lindsay N
authors.initials: LN
authors.lastname: Boyers
authors.affiliation: Dermatology Service, U.S. Department of Veterans Affairs, Eastern Colorado Health Care System, Denver, Colorado, USA University of Colorado, School of Medicine, Aurora, Colorado, USA Department of Epidemiology, Colorado School of Public Health, University of Colorado, Aurora, Colorado, USA.
authors.forename: Robert P
authors.initials: RP
authors.lastname: Dellavalle
authors.affiliation: Cochrane Editorial Unit, The Cochrane Collaboration, London, UK.
authors.forename: John
authors.initials: J
authors.lastname: Hilton
authors.affiliation: Hunter New England Population Health, Wallsend, New South Wales, Australia The University of Newcastle, School of Medicine and Public Health, Callaghan, New South Wales, Australia Hunter Medical Research Institute, New Lambton, New South Wales, Australia.
authors.forename: Luke
authors.initials: L
authors.lastname: Wolfenden
mesh_terms: D015706:Bibliometrics; D017281:Cost of Illness; D016208:Databases, Factual; D006233:Persons with Disabilities / Q000706:statistics & numerical data*; D006801:Humans; D009026:Mortality / Q000639:trends*; D012196:Review Literature as Topic
keywords: EPIDEMIOLOGY; MORBIDITY; MORTALITY; STATISTICS; SYSTEMATIC REVIEWS