Figure 7

Nomogram of the combined model. A nomogram is a visual tool used to apply predictive models in clinical practice. It allows for the visualization of how different values of individual variables influence the final prediction outcome. In this nomogram, the top line (“Points” scale) serves as the reference for scoring points for each predictor from 0 to 100. The predictive variables, including Rad-score, body temperature, age, and neutrophil percentage, are displayed below with bars that represent their effect size, visually demonstrating the relative weight of each variable. These lines are plotted to assign points to each significant clinical characteristic. The sum of points from the above predictors can be checked on the “Total Points” scale, and then the corresponding predicted probability of non-simple appendicitis can be read from the bottom line (“non-Simple Appendicitis Possibility” scale). For example, using the following information from a patient to predict the likelihood of non-simple appendicitis: 35 years old, body temperature of 37.4 degrees Celsius, neutrophil percentage of 70%, and Rad-score of 0.60. Points are allocated accordingly on the “Points” scale: 35 years old corresponds to 12.922 points, 37.4 degrees Celsius corresponds to 36.024 points, neutrophil percentage of 70% corresponds to 11.575 points, and Rad-score of 0.60 corresponds to 53.846 points. Total Points = 12.922 (age) + 36.024 (body temperature) + 11.575 (neutrophil percentage) + 53.846 (Rad-score) = 114.367 points. We can locate 114.367 points on the “Total Points” scale by drawing a line down to the "non-Simple Appendicitis Probability” scale, indicating a 70% chance of a non-simple appendicitis case.