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Table 1 Predictors and regression coefficients of the original and updated models

From: Evaluating the impact of prediction models: lessons learned, challenges, and recommendations

Original model Updated model
Predictor Regression coefficients Predictor
Age (years) − 0.022 − 0.017 Age (years)
Female gender 0.46 0.36 Female gender
Current smoking − 0.63 − 0.50 Current smoking
History of PONV or motion sickness 0.76 0.60 History of PONV or motion sickness
Lower abdominal or middle ear surgery 0.61 0.48 Abdominal or middle ear surgerya
Isoflurane and/or nitrous oxide anesthesiab 0.72 0.35 Inhalational anesthesiab
  − 1.16 Outpatient surgeryc
Intercept 0.15 0.12 Intercept
  Model performance characteristicsd  
Model discrimination as C-statistic (95% CI) 0.62 (0.60–0.64) 0.68 (0.66–0.70) Model discrimination as C-statistic (95% CI)
Calibration slope (95% CI) 0.57 (0.48–0.66) 1.00 (0.89–1.10) Calibration slope (95% CI)
  1. PONV postoperative nausea and vomiting, CI confidence interval
  2. aIn the updated model, the predictor included lower abdominal, upper abdominal, and laparoscopic surgery in addition to middle ear surgery
  3. bAs compared to intravenous anesthesia using propofol
  4. cPredictor not included in the original model, but added in the update of the model
  5. dModel performance was validated in a subset of patients (between March 2006 and February 2007) treated by anesthesiologists of the care-as-usual group of the cluster-randomized trial [19]