title: Assessment of cognitive biases and biostatistics knowledge of medical residents: a multicenter, cross-sectional questionnaire study.
abstract: OBJECTIVE
  The aim of this study is to determine the perceived familiarity of medical residents with statistical concepts, assess their ability to integrate these concepts in clinical scenarios, and investigate their susceptibility to the gambler's fallacy and the conjunction fallacy.
  
  
  METHODS
  A multi-institutional, cross-sectional survey of Greek medical residents was performed. Participants were asked to indicate their familiarity with basic statistical concepts and answer clinically oriented questions designed to assess their biostatistics knowledge and cognitive biases. Univariate, bivariate, and multivariate statistical models were used for the evaluation of data.
  
  
  RESULTS
  Out of 153 respondents (76.5% response rate), only two participants (1.3%) were able to answer all seven biostatistics knowledge questions correctly while 29 residents (19%) gave incorrect answers to all questions. The proportion of correct answers to each biostatistics knowledge question ranged from 15 to 51.6%. Residents with greater self-reported familiarity were more likely to perform better on the respective knowledge question (all p<0.01). Multivariate analysis of the effect of individual resident characteristics on questionnaire performance showed that previous education outside Greece, primarily during medical school, was associated with lower biostatistics knowledge scores (p<0.001). A little more than half of the respondents (54.2%) answered the gambler's fallacy quiz correctly. Residents with higher performance on the biostatistics knowledge questions were less prone to the gambler's fallacy (odds ratio 1.38, 95% confidence intervals 1.12-1.70, p=0.003). Only 48 residents (31.4%) did not violate the conjunction rule.
  
  
  CONCLUSIONS
  A large number of medical residents are unable to correctly interpret crucial statistical concepts that are commonly found in the medical literature. They are also especially prone to the gambler's fallacy bias, which may undermine clinical judgment and medical decision making. Formalized systematic teaching of biostatistics during residency will be required to de-bias residents and ensure that they are proficient in understanding and communicating statistical information.
authors.affiliation: Greek Junior Doctors and Health Scientists Society, Athens, Greece; msaouel@gmail.com.
authors.forename: Pavlos
authors.initials: P
authors.lastname: Msaouel
authors.affiliation: 2nd Department of Surgery, Metaxa Cancer Memorial Hospital, Pireaus, Greece.
authors.forename: Theocharis
authors.initials: T
authors.lastname: Kappos
authors.affiliation: Department of Clinical Therapeutics, Alexandra Hospital, Athens, Greece.
authors.forename: Athanasios
authors.initials: A
authors.lastname: Tasoulis
authors.affiliation: Department of Orthopaedics, Asklipiio Hospital, Athens, Greece.
authors.forename: Alexandros P
authors.initials: AP
authors.lastname: Apostolopoulos
authors.affiliation: Otorhinolaryngology Clinic, 251 G.N.A. Hospital, Athens, Greece.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Lekkas
authors.affiliation: 1st Department of Internal Medicine, Evangelismos Hospital, Athens, Greece.
authors.forename: Elli-Sophia
authors.initials: ES
authors.lastname: Tripodaki
authors.affiliation: Greek Junior Doctors and Health Scientists Society, Athens, Greece.
authors.forename: Nikolaos C
authors.initials: NC
authors.lastname: Keramaris
mesh_terms: D000328:Adult; D056808:Biostatistics; D003071:Cognition; D003430:Cross-Sectional Studies; D005260:Female; D006115:Greece; D006801:Humans; D007396:Internship and Residency / Q000706:statistics & numerical data*; D019359:Knowledge; D008297:Male; D013337:Students, Medical / Q000706:statistics & numerical data*; D011795:Surveys and Questionnaires
keywords: biostatistics knowledge; cognitive bias; conjunction fallacy; gambler's fallacy; medical residents; statistical literacy