title: Evidence Underlying KDIGO (Kidney Disease: Improving Global Outcomes) Guideline Recommendations: A Systematic Review.
abstract: BACKGROUND
  The KDIGO (Kidney Disease: Improving Global Outcomes) clinical practice guidelines establish international recommendations for the definition and treatment of kidney disease. Our objective was to characterize the strength of evidence supporting the KDIGO guidelines, the class of recommendations made, and the relationship between these.
  
  
  METHODS
  We reviewed and abstracted the level of evidence and strength of recommendations in the currently available KDIGO guidelines.
  
  
  METHODS
  KDIGO clinical practice guidelines target care of patients with kidney disease to improve outcomes.
  
  
  METHODS
  All KDIGO guidelines published on the KDIGO website as of November 2013 were included.
  
  
  METHODS
  Recommendations pertaining to disease, diagnosis, or treatment.
  
  
  RESULTS
  Levels of evidence and strength of recommendations.
  
  
  RESULTS
  Of 853 recommendations in 9 guidelines, 5% were supported by level A quality evidence; 17%, level B; 31%, level C; 18%, level D; and 20%, ungraded evidence. The strength of recommendations was class 1 for 25%, class 2 for 54%, and ungraded for 20%. Only 3% of recommendations were class 1 in strength and supported by level A evidence. Of the recommendations, 2% concerned disease definition and classification; 29%, diagnosis; and 69%, treatment.
  
  
  CONCLUSIONS
  Our study included only the KDIGO guidelines. We did not assess historical changes in nephrology guidelines recommendations.
  
  
  CONCLUSIONS
  KDIGO recommendations were based largely on weak evidence, reflecting expert opinion. Few recommendations were both strong and supported by high-level evidence.
authors.affiliation: Division of Clinical Decision Making, Tufts Medical Center, Boston, MA.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Alseiari
authors.affiliation: William B. Schwartz Division of Nephrology, Tufts Medical Center, Boston, MA.
authors.forename: Klemens B
authors.initials: KB
authors.lastname: Meyer
authors.affiliation: Division of Clinical Decision Making, Tufts Medical Center, Boston, MA. Electronic address: jwong@tuftsmedicalcenter.org.
authors.forename: John B
authors.initials: JB
authors.lastname: Wong
mesh_terms: D055317:Evidence-Based Practice; D006801:Humans; D007674:Kidney Diseases / Q000628:therapy*; D009398:Nephrology / Q000379:methods / Q000592:standards; D017410:Practice Guidelines as Topic / Q000592:standards*; D058996:Quality Improvement
keywords: Evidence-based medicine; KDIGO (Kidney Disease: Improving Global Outcomes); clinical practice guidelines; kidney disease; nephrology; quality of evidence; renal; strength of recommendation