title: Outcomes Definitions and Statistical Tests in Oncology Studies: A Systematic Review of the Reporting Consistency.
abstract: BACKGROUND
  Quality of reporting for Randomized Clinical Trials (RCTs) in oncology was analyzed in several systematic reviews, but, in this setting, there is paucity of data for the outcomes definitions and consistency of reporting for statistical tests in RCTs and Observational Studies (OBS). The objective of this review was to describe those two reporting aspects, for OBS and RCTs in oncology.
  
  
  METHODS
  From a list of 19 medical journals, three were retained for analysis, after a random selection: British Medical Journal (BMJ), Annals of Oncology (AoO) and British Journal of Cancer (BJC). All original articles published between March 2009 and March 2014 were screened. Only studies whose main outcome was accompanied by a corresponding statistical test were included in the analysis. Studies based on censored data were excluded. Primary outcome was to assess quality of reporting for description of primary outcome measure in RCTs and of variables of interest in OBS. A logistic regression was performed to identify covariates of studies potentially associated with concordance of tests between Methods and Results parts.
  
  
  RESULTS
  826 studies were included in the review, and 698 were OBS. Variables were described in Methods section for all OBS studies and primary endpoint was clearly detailed in Methods section for 109 RCTs (85.2%). 295 OBS (42.2%) and 43 RCTs (33.6%) had perfect agreement for reported statistical test between Methods and Results parts. In multivariable analysis, variable "number of included patients in study" was associated with test consistency: aOR (adjusted Odds Ratio) for third group compared to first group was equal to: aOR Grp3 = 0.52 [0.31-0.89] (P value = 0.009).
  
  
  CONCLUSIONS
  Variables in OBS and primary endpoint in RCTs are reported and described with a high frequency. However, statistical tests consistency between methods and Results sections of OBS is not always noted. Therefore, we encourage authors and peer reviewers to verify consistency of statistical tests in oncology studies.
authors.affiliation: Department of Medical Oncology Lucien Neuwirth Cancer Institute, Saint Priest en Jarez, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Rivoirard
authors.affiliation: Department of Public Health, Hygée Center, Saint Priest en Jarez, France.|Inserm, Clinical Investigation Center 1408, 42055 Saint-Etienne, France.
authors.forename: Vianney
authors.initials: V
authors.lastname: Duplay
authors.affiliation: Department of Public Health, Hygée Center, Saint Priest en Jarez, France.|Inserm, Clinical Investigation Center 1408, 42055 Saint-Etienne, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Oriol
authors.affiliation: Department of Public Health, Hygée Center, Saint Priest en Jarez, France.|Inserm, Clinical Investigation Center 1408, 42055 Saint-Etienne, France.
authors.forename: Fabien
authors.initials: F
authors.lastname: Tinquaut
authors.affiliation: Department of Public Health, Hygée Center, Saint Priest en Jarez, France.|Inserm, Clinical Investigation Center 1408, 42055 Saint-Etienne, France.
authors.forename: Franck
authors.initials: F
authors.lastname: Chauvin
authors.affiliation: Department of Radiation Therapy Lucien Neuwirth Cancer Institute, Saint Priest en Jarez, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Magne
authors.affiliation: Department of Public Health, Hygée Center, Saint Priest en Jarez, France.|Inserm, Clinical Investigation Center 1408, 42055 Saint-Etienne, France.
authors.forename: Aurelie
authors.initials: A
authors.lastname: Bourmaud
mesh_terms: D006801:Humans; D008495:Medical Oncology / Q000592:standards* / Q000706:statistics & numerical data*; D066209:Medical Writing / Q000592:standards; D011643:Publishing / Q000592:standards*; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data; D058028:Research Report / Q000592:standards*