title: The landscape of clinical trials in nephrology: a systematic review of Clinicaltrials.gov.
abstract: BACKGROUND
  Well-designed trials are of paramount importance in improving the delivery of care to patients with kidney disease. However, it remains unknown whether contemporary clinical trials within nephrology are of sufficient quality and quantity to meet this need.
  
  
  METHODS
  Systematic review.
  
  
  METHODS
  Studies registered with ClinicalTrials.gov.
  
  
  METHODS
  Interventional (ie, nonobservational) studies (both randomized and nonrandomized) registered between October 2007 and September 2010 were included for analysis. Studies were reviewed independently by physicians and classified by clinical specialty.
  
  
  METHODS
  Nephrology versus cardiology versus other trials.
  
  
  RESULTS
  Select clinical trial characteristics.
  
  
  RESULTS
  Of 40,970 trials overall, 1,054 (2.6%) were classified as nephrology. Most nephrology trials were for treatment (75.4%) or prevention (15.7%), with very few diagnostic, screening, or health services research studies. Most nephrology trials were randomized (72.3%). Study designs included 24.9% with a single study group, 64.0% that included parallel groups, and 9.4% that were crossover trials. Nephrology trials, compared with 2,264 cardiology trials (5.5% overall), were more likely to be smaller (64.5% vs 48.0% enrolling≤100 patients), phases 1-2 (29.0% vs 19.7%), and unblinded (66.2% vs 53.3%; P<0.05 for all). Nephrology trials also were more likely than cardiology trials to include a drug intervention (72.4% vs 41.9%) and less likely to report having a data monitoring committee (40.3% vs 48.5%; P<0.05 for all). Finally, there were few trials funded by the National Institutes of Health (NIH; 3.3%, nephrology; 4.2%, cardiology).
  
  
  CONCLUSIONS
  Does not include all trials performed worldwide, and frequent categorization of funding source as university may underestimate NIH support.
  
  
  CONCLUSIONS
  Critical differences remain between clinical trials in nephrology and other specialties. Improving care for patients with kidney disease will require a concerted effort to increase the scope, quality, and quantity of clinical trials within nephrology.
authors: Duke University Medical Center, Durham, NC; Quintiles Global Clinical Research Organization, Morrisville, NC.
authors: Jula K
authors: JK
authors: Inrig
authors: Duke University Medical Center, Durham, NC.
authors: Robert M
authors: RM
authors: Califf
authors: Duke University Medical Center, Durham, NC.
authors: Asba
authors: A
authors: Tasneem
authors: University of Illinois, Urbana, IL.
authors: Radha K
authors: RK
authors: Vegunta
authors: University of Texas Southwestern Medical Center, Dallas, TX.
authors: Christopher
authors: C
authors: Molina
authors: Duke University Medical Center, Durham, NC.
authors: John W
authors: JW
authors: Stanifer
authors: Duke University Medical Center, Durham, NC.
authors: Karen
authors: K
authors: Chiswell
authors: Duke University Medical Center, Durham, NC. Electronic address: uptal.patel@duke.edu.
authors: Uptal D
authors: UD
authors: Patel
mesh_terms: D002986:Clinical Trials as Topic / Q000379:methods*; D006801:Humans; D020407:Internet; D007674:Kidney Diseases / Q000628:therapy*; D009398:Nephrology / Q000379:methods*; D014481:United States
keywords: Chronic kidney disease; end-stage renal disease; kidney transplantation; randomized controlled trial; systematic review