Figure 2From: Validation of prediction models based on lasso regression with multiply imputed data An algorithm to calculate optimism in the presence of multiply imputed data based on Harrell [6]. The true performance =Apparent (Step 3 in the Model performance: discrimination and calibration section) - mean (B Optimism ∗’s). B is the number of bootstrap samples and ∗ is used to denote bootstrap objects.Back to article page