title: Influence of the way results are presented on research interpretation and medical decision making: the PRIMER collaboration randomized studies.
abstract: BACKGROUND
  The manner of presentation of research results may affect how clinicians interpret research and make clinical decisions. The authors evaluate whether the use of confidence levels improve research interpretation and decision making compared with P values and 95% confidence intervals.
  
  
  METHODS
  The 2 Presentation and Interpretation of Medical Research (PRIMER) studies were 3-arm randomized trials. PRIMER 1 presented results of 5 fictitious scenarios with P values (P), P plus 95% confidence intervals (P + CI), or P, CI, and confidence levels (P + CI + CL); PRIMER 2 compared P + CI + CL, P + CI, and P + CL. Clinicians were asked to identify the correct interpretation of scenarios in terms of statistical and clinical significance and then indicate the intended decision making in terms of treatment recommendation.
  
  
  RESULTS
  Seventy-five and 246 clinicians participated in PRIMER 1 and PRIMER 2, respectively. In PRIMER 1, P+CI+CL was superior to P + CI and P (P < 0.05); the latter 2 arms did not differ significantly. Decision making was not significantly different between arms. In PRIMER 2, P+CI+CL resulted in better interpretation than P + CI (P = 0.03), with no difference between P + CI and P + CL. In combined analysis, the odds of correct interpretation were higher for P+CI+CL than P+CI (odds ratio = 1.73, P=0.005, 95% CI= 1.19--2.52). Decision making was better for P + CI+ CL (P = 0.03). On multivariate analysis, the P + CI+ CL arm and clinicians with statistics training, not in private practice, or participating in PRIMER 1 had better interpretation. The P + CI+ CL arm was the only factor improving decision making.
  
  
  CONCLUSIONS
  Presenting research with a combination of P values, confidence intervals, and confidence levels leads to better interpretation and decision making by clinicians.
authors: North Coast Cancer Institute, Coffs Harbour Health Campus, Coffs Harbour, New South Wales, Australia. thomasshakespeare@gmail.com
authors: Thomas Philip
authors: TP
authors: Shakespeare
authors: Val
authors: V
authors: Gebski
authors: Johann
authors: J
authors: Tang
authors: Keith
authors: K
authors: Lim
authors: Jiade Jay
authors: JJ
authors: Lu
authors: Xiaojian
authors: X
authors: Zhang
authors: Guoliang
authors: G
authors: Jiang
mesh_terms: D000328:Adult; D016001:Confidence Intervals; D003627:Data Interpretation, Statistical; D003657:Decision Making; D005260:Female; D006801:Humans; D033181:Information Dissemination / Q000379:methods*; D008297:Male; D009517:New South Wales; D016032:Randomized Controlled Trials as Topic; D012106:Research / Q000706:statistics & numerical data; D011795:Surveys and Questionnaires