To develop a diagnostic model based on multi-parameter ultrasound for stress urinary incontinence (SUI) in middle-aged and elderly women and assess its application value.

The clinical and ultrasonographic data of 197 middle-aged and elderly women, including 127 SUI patients and 70 non-SUI patients, from the Pelvic Floor Diagnostic and Treatment Center of Xiangya Hospital of Central South University from March 2021 to May 2023, were retrospectively analyzed in this study. All the subjects were randomly divided into a training group (n=137) anda validation group (n=60) at a ratio of 7∶3. In the training group, univariable analysis and multivariable logistic regression analysis were used to select the indicators. Then, a nomogram diagnostic model was established. The discrimination, calibration, and clinical applicability of the model were evaluated by the area under the curve (AUC), Hosmer-Lemeshow test, calibration curve, and decision curve analysis.

Vaginal delivery (odds ratio [OR]=11.256, 95% confidence interval [CI]: 1.275-99.405, P=0.029), internal urethral orifice funnel (OR=10.552, 95%CI: 2.427-45.886, P=0.002), increased bladder neck mobility (OR=1.072, 95%CI: 1.010-1.138, P=0.022), and increased posterior retrovesical angle (OR=1.042, 95%CI: 1.014-1.070, P=0.003) were included in the diagnostic model. The AUC values of the model in the training group and validation group were 0.952 (95%CI: 0.921-0.983) and 0.897 (95%CI: 0.813-0.982 ), respectively. The results of the Hosmer-Lemeshow test (χ²=4.282, P=0.892, χ²=10.556, P=0.307) and calibration curve analysis exhibited good calibration. The clinical decision curve indicated good net gain.

The nomogram model developed based on multi-parameter ultrasound has good diagnostic performance for SUI in middle-aged and elderly women, providing a more objective basis for clinical diagnosis.