This web-based calculator estimates the probability of loss to follow-up in solitary kidney stone patients after surgery, based on a multivariable logistic regression nomogram developed from a prospective cohort of 332 patients. The model incorporates 11 clinical predictors and achieved an AUC of 0.826 (95% CI: 0.783–0.868) with Bootstrap internal validation (1,000 resamples).
Enter Patient Information
Predicted Risk
Estimated probability of loss to follow-up within the post-operative period.
Low risk: <30% · Moderate risk: 30–50% · High risk: >50%
Nomogram
Figure 1. Nomogram for predicting loss to follow-up in solitary kidney stone patients after surgery. Click image to enlarge.
Model Performance
| Metric | Value |
|---|---|
| Sample Size | 332 patients (117 lost to follow-up, 35.2%) |
| AUC (Bootstrap-corrected) | 0.826 (95% CI: 0.783–0.868) |
| Calibration Intercept | 0.081 |
| Calibration Slope | 1.194 |
| Internal Validation | 1,000× Bootstrap resampling |
Figure 2. Calibration curve (Bootstrap-corrected).
Figure 3. ROC curve (AUC = 0.826).
Disclaimer
This tool is intended for clinical reference only and should not replace professional medical judgment. Predictions are estimates derived from a single-center prospective cohort study and may not generalize to all populations. External validation is required before widespread clinical application.
Results should be interpreted in the context of each patient's individual clinical circumstances. Clinicians are encouraged to use this calculator as one component of a comprehensive follow-up planning strategy.