RMS Describing, Resampling, Validating, and Simplifying the Model

[FurlanLeo]

Thank you Professor!

Here are the results of my updated analysis.
Please, any comments or suggestions for improving it?

1. Chunk test / likelihood ratio chi-square test for added predictive value of the clinical measures altogether:

#   Chi-Square         d.f.            P 
# 6.386165e+01 7.000000e+00 2.545708e-11

2. REV (500 bootstrap resamples of the full model):
   

   

3. Fit x4 model:
   lrm(formula = y ~ DOM + BAM + SEX + rcs(AGE, 3) + rcs(x4, 3),
data = data, x = T, y = T)

4. Anova (Likelihood Ratio Statistics):
   Significant association of AGE (df=2; p=0.0007) and x4 (df=2; p<0.0001)

5. Bootstrap model and partial effects plots:
   

   

6. Model validation with bootstrap (B=500):
   Somer’s D (corrected index) = 0.5455

7. Model calibration with bootstrap (B=500):
   Mean absolute error = 0.014
   0.9 Quantile of absolute error = 0.025
   

   

8. Nomogram: