Additional file 1: of Using Bayesian statistics to estimate the likelihood a new trial will demonstrate the efficacy of a new treatment

Bayesian Analyses. (DOCX 21 kb

Box plots comparing surgeon-patient differences between surgeons.

<p>Boxes include the first quartile, the median and the third quartile. Surgeons 4 to 8, who recruited 5–11 patients each, and surgeons 9 to 16, who recruited 1–3 patients each, were aggregated.</p

Determinants of patients' or surgeons' expectation (total THR Survey score, max = 100).^*

<p>*Bold characters indicate significative tests; NS = Numeric Scale; WOMAC = Western Ontario and McMaster Universities Osteoarthritis Index; SF-12 = Medical Outcome Study Short Form-12; PCS = Physical Component Summary; MCS = Medical Component Summary.</p

Bland and Altman graph of differences in expectations (surgeon's score – patient's score).

<p>For each patient, X-axis represents mean (½×(surgeon's score+patient's score)), Y-axis represents difference. The three tertiles-defined groups of patients are represented by three colors (red = “more optimistic patients”; blue = middle group, purple = “more pessimistic patients”).</p

Comparison between patients more optimistic than his surgeon and patients more pessimistic.

<p>Bold characters indicate significative tests; NS = Numeric Scale; WOMAC = Western Ontario and McMaster Universities Osteoarthritis Index; SF-12 = Medical Outcome Study Short Form 12; PCS = Physical Component Summary; MCS = Medical Component Summary.</p>1<p> = comparisons using chi-square tests and ANOVAs.</p>2<p> = comparisons using mixed effect logistic models (random effects = surgeon).</p

Characteristics of study population (n = 132).^*

<p>*THA = Total Hip Arthroplasty; NS = Numeric Scale; WOMAC = Western Ontario and McMaster Universities Osteoarthritis Index; SF-12 = Medical Outcome Study Short Form-12; PCS = Physical Component Summary; MCS = Medical Component Summary.</p

Scatter plot of patients' versus surgeons' expectations.

<p>Scatter plot of patients' versus surgeons' expectations.</p