Pain and global assessment were measured using the Visual Analogue Scale and patient global assessment (VAS and VASg) whose scores range from 0 to 10. Laboratory measures of inflammation, such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), were regularly assessed in all the patients (normal values for our laboratory: <0.6 mg/dL for CRP and <20 mm/hour for ESR).
Specifically, perceptions of challenge (three items, α = 0.74), responsibility (three items, α = 0.78), threat (three items, α = 0.87), and control (two items, α not applicable), which altogether make up perceptual assessment, were measured using a five-point Likert-type scale ranging from strongly disagree to strongly agree.
The reliability (concordance of assessments) was measured using the method proposed by Landis and Koch [ 32].
Between group effect sizes for the outcome assessments were measured using Cohen's d using unadjusted means for the dependent variables and SD pooled for unequal group sizes.
Safety assessments were measured using adverse-event (AE) monitoring, clinical laboratory parameters, fundoscopy, physical and neurological examination, and vital-sign measurements.
The present study may underestimate or overestimate baseline prevalence rates, but these ECG assessments were measured using computer technology that is more contemporary than the methods used for currently referenced norms, such as those presented by Davignon et al. [ 4].
To address any residual confounding after randomization, we adjusted for several covariates: trainee profession, the two strata (CQI experienced and presence of BIPAI at the facility), and learning during the assessment, which was measured using a categorical variable taking on values of one to five for the sequence of the particular patient being observed for each trainee.
The reliability of pain assessment scores was measured using inter-rater reliability (agreement between raters), test-retest (extent to which a tool achieves the same result on two or more occasions when the condition is stable) or intra-rater reliability (agreement of the same rater at different time points) and internal consistency (Additional file 9).
