title: Loss to analysis in randomized controlled trials in CKD.
abstract: BACKGROUND
  Nephrology has a limited number of randomized controlled trials (RCTs). The quality of randomized trials is compromised further when not all participants randomly assigned are accounted for transparently.
  
  
  OBJECTIVE
  Systematically evaluate RCTs in individuals with chronic kidney disease regarding reporting and accounting of data missing in outcome analysis.
  
  
  METHODS
  De novo empirical evaluation.
  
  
  METHODS
  English-language parallel-group design RCTs in adults with chronic kidney disease on dialysis therapy or with a kidney transplant published in MEDLINE in 2007 and 2008.
  
  
  METHODS
  (1) How often was there loss to analysis, defined as not all randomly assigned participants included in primary outcome analysis? (2) How often was intention-to-treat analysis complete; in other words, included all randomly assigned participants in their originally allocated group? (3) How often were methods of data imputation reported?
  
  
  RESULTS
  Of 196 eligible RCTs, 27% did not clearly describe a primary outcome, 5% did not provide numbers of patients randomly assigned and analyzed, and 12% used time-to-event analysis. Of the remaining 110 studies, 58% had some loss to analysis, with a median loss to analysis of 10%. Fifty-four percent of trials claimed to have performed an intention-to-treat analysis, but only 44% of those included all participants randomly assigned. Only 5 of 110 (5%) studies mentioned imputation of missing data.
  
  
  CONCLUSIONS
  Evaluation is restricted to analysis of primary study outcome. Only English-language publications were included. Exclusion of time-to-event analyses.
  
  
  CONCLUSIONS
  In variance to the reporting standards of CONSORT (Consolidated Standards of Reporting Trials), we found primary outcome designation missing in one-fourth of trials and poor quality in reporting and accounting of primary outcome data lost to analysis. Greater attention to transparency in handling and reporting loss to analysis will enhance the quality of trials in individuals with chronic kidney disease.
authors.affiliation: Division of Nephrology, Department of Medicine, Tufts Medical Center, Boston, MA 02111, USA.
authors.forename: Aneet
authors.initials: A
authors.lastname: Deo
authors.forename: Christopher H
authors.initials: CH
authors.lastname: Schmid
authors.forename: Amy
authors.initials: A
authors.lastname: Earley
authors.forename: Joseph
authors.initials: J
authors.lastname: Lau
authors.forename: Katrin
authors.initials: K
authors.lastname: Uhlig
mesh_terms: D006801:Humans; D057194:Intention to Treat Analysis / Q000592:standards; D009398:Nephrology; D017063:Outcome Assessment, Health Care / Q000592:standards*; D010506:Periodicals as Topic / Q000706:statistics & numerical data; D016032:Randomized Controlled Trials as Topic / Q000592:standards*; D051436:Renal Insufficiency, Chronic / Q000628:therapy*