title: Do Orthopaedic Surgeons Acknowledge Uncertainty?
abstract: BACKGROUND
  Much of the decision-making in orthopaedics rests on uncertain evidence. Uncertainty is therefore part of our normal daily practice, and yet physician uncertainty regarding treatment could diminish patients' health. It is not known if physician uncertainty is a function of the evidence alone or if other factors are involved. With added experience, uncertainty could be expected to diminish, but perhaps more influential are things like physician confidence, belief in the veracity of what is published, and even one's religious beliefs. In addition, it is plausible that the kind of practice a physician works in can affect the experience of uncertainty. Practicing physicians may not be immediately aware of these effects on how uncertainty is experienced in their clinical decision-making.
  
  
  OBJECTIVE
  We asked: (1) Does uncertainty and overconfidence bias decrease with years of practice? (2) What sociodemographic factors are independently associated with less recognition of uncertainty, in particular belief in God or other deity or deities, and how is atheism associated with recognition of uncertainty? (3) Do confidence bias (confidence that one's skill is greater than it actually is), degree of trust in the orthopaedic evidence, and degree of statistical sophistication correlate independently with recognition of uncertainty?
  
  
  METHODS
  We created a survey to establish an overall recognition of uncertainty score (four questions), trust in the orthopaedic evidence base (four questions), confidence bias (three questions), and statistical understanding (six questions). Seven hundred six members of the Science of Variation Group, a collaboration that aims to study variation in the definition and treatment of human illness, were approached to complete our survey. This group represents mainly orthopaedic surgeons specializing in trauma or hand and wrist surgery, practicing in Europe and North America, of whom the majority is involved in teaching. Approximately half of the group has more than 10 years of experience. Two hundred forty-two (34%) members completed the survey. We found no differences between responders and nonresponders. Each survey item measured its own trait better than any of the other traits. Recognition of uncertainty (0.70) and confidence bias (0.75) had relatively high Cronbach alpha levels, meaning that the questions making up these traits are closely related and probably measure the same construct. This was lower for statistical understanding (0.48) and trust in the orthopaedic evidence base (0.37). Subsequently, combining each trait's individual questions, we calculated a 0 to 10 score for each trait. The mean recognition of uncertainty score was 3.2 ± 1.4.
  
  
  RESULTS
  Recognition of uncertainty in daily practice did not vary by years in practice (0-5 years, 3.2 ± 1.3; 6-10 years, 2.9 ± 1.3; 11-20 years, 3.2 ± 1.4; 21-30 years, 3.3 ± 1.6 years; p = 0.51), but overconfidence bias did correlate with years in practice (0-5 years, 6.2 ± 1.4; 6-10 years, 7.1 ± 1.3; 11-20 years, 7.4 ± 1.4; 21-30 years, 7.1 ± 1.2 years; p < 0.001). Accounting for a potential interaction of variables using multivariable analysis, less recognition of uncertainty was independently but weakly associated with working in a multispecialty group compared with academic practice (β regression coefficient, -0.53; 95% confidence interval [CI], -1.0 to -0.055; partial R(2), 0.021; p = 0.029), belief in God or any other deity/deities (β, -0.57; 95% CI, -1.0 to -0.11; partial R(2), 0.026; p = 0.015), greater confidence bias (β, -0.26; 95% CI, -0.37 to -0.14; partial R(2), 0.084; p < 0.001), and greater trust in the orthopaedic evidence base (β, -0.16; 95% CI, -0.26 to -0.058; partial R(2), 0.040; p = 0.002). Better statistical understanding was independently, and more strongly, associated with greater recognition of uncertainty (β, 0.25; 95% CI, 0.17-0.34; partial R(2), 0.13; p < 0.001). Our full model accounted for 29% of the variability in recognition of uncertainty (adjusted R(2), 0.29).
  
  
  CONCLUSIONS
  The relatively low levels of uncertainty among orthopaedic surgeons and confidence bias seem inconsistent with the paucity of definitive evidence. If patients want to be informed of the areas of uncertainty and surgeon-to-surgeon variation relevant to their care, it seems possible that a low recognition of uncertainty and surgeon confidence bias might hinder adequately informing patients, informed decisions, and consent. Moreover, limited recognition of uncertainty is associated with modifiable factors such as confidence bias, trust in orthopaedic evidence base, and statistical understanding. Perhaps improved statistical teaching in residency, journal clubs to improve the critique of evidence and awareness of bias, and acknowledgment of knowledge gaps at courses and conferences might create awareness about existing uncertainties.
  
  
  METHODS
  Level 1, prognostic study.
authors.affiliation: General Surgery, Onze Lieve Vrouwe Gasthuis, Amsterdam, The Netherlands.
authors.forename: Teun
authors.initials: T
authors.lastname: Teunis
authors.affiliation: Musculoskeletal Oncology Service, Massachusetts General Hospital-Harvard Medical School, Boston, MA, USA.
authors.forename: Stein
authors.initials: S
authors.lastname: Janssen
authors.affiliation: Orthopaedic Surgery, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Thierry G
authors.initials: TG
authors.lastname: Guitton
authors.affiliation: Orthopaedic Hand and Upper Extremity Service, Massachusetts General Hospital-Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA. dring@mgh.harvard.edu.
authors.forename: David
authors.initials: D
authors.lastname: Ring
authors.affiliation: Orthopaedic Surgery, Elliot Hospital, Manchester, NH, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Parisien
mesh_terms: D001291:Attitude of Health Personnel; D015982:Bias; D002983:Clinical Competence; D003627:Data Interpretation, Statistical; D019317:Evidence-Based Medicine / Q000706:statistics & numerical data; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D016014:Linear Models; D008297:Male; D015999:Multivariate Analysis; D000072161:Orthopedic Surgeons / Q000523:psychology*; D000071836:Professional Practice Gaps; D021641:Recognition, Psychology; D012068:Religion and Medicine; D011795:Surveys and Questionnaires; D035502:Trust; D035501:Uncertainty