Table 1

Rasch model item statistics of the rating scale model for confounding factors impacting surgical decision-making.

Test ItemsMeasureSE MeasureInfitOutfit
Comfort−1.3530.1330.9240.809
Patient−1.1590.1221.4481.542
Outcome−0.9930.1140.9360.963
Instruments−0.8670.1100.7610.749
Rehab−0.7850.1071.0581.048
Model FitPerson ReliabilityP
Scale0.3810.061
  • Note: Infit = Information-weighted mean square based on the χ2 statistic with each observation weighted by its statistical information (model variance). This is more sensitive to unexpected patterns of observations by persons on items that are roughly targeted at them (and vice-versa). Outfit = Outlier-sensitive means square statistic is more sensitive to unexpected observations by surgeons. Infit and outfit data between 0.6 and 1.4 indicate good fit of the Rasch model. MADaQ3 = Mean of absolute values of centered Q_3 statistic with P value obtained by Holm adjustment; Ho = the data fit the Rasch model.