Stress urinary incontinence (SUI) is a prevalent condition with a substantial impact on quality of life. Although urodynamic testing remains the reference standard for diagnosis and severity assessment, its routine use is controversial due to its invasive nature and associated cost. Non-invasive tools, including pad testing, patient-reported outcome measures (ICIQ-UI-SF, ICIQ-FLUTS), and the 1–3–5 cough stress test (CST), are widely used in clinical practice. However, limited data exist regarding their ability to accurately reflect SUI severity and discriminate between severity levels.
This study aimed to evaluate and compare the performance of these non-invasive methods in assessing SUI severity, using urodynamic findings as the reference standard.

A retrospective study was conducted including 120 consecutive women presenting with symptoms of SUI (Table 1) who underwent multichannel urodynamic evaluation in a tertiary academic center. All participants underwent standardized clinical assessment, including the      1–3–5 CST, 1-hour pad test, validated questionnaires (ICIQ-UI-SF, ICIQ-FLUTS), and urodynamic testing (UDS CST).
The 1–3–5 CST was performed in the standing position with a comfortably full bladder independently of  urodynamics. The 1-hour pad test was conducted according to standardized methodology.[1] The ICS Uniform Cough Stress Test (ICS-UCST) was performed during urodynamics with bladder volume ~300 mL or at functional capacity, in supine and/or standing position. A stepwise cough protocol (1–3–5) was applied, with increasing number of coughs until leakage occurred; earlier leakage indicated greater severity. Patients were classified as having mild, moderate, or severe urodynamic stress incontinence (USI) according to ICS-UCST criteria [2]. 
Receiver operating characteristic (ROC) analysis was performed to evaluate diagnostic performance, alongside calculation of sensitivity and specificity using clinically relevant cut-off values.

According to ICS-UCST, patients were classified as mild (n=21), moderate (n=43), or severe (n=56) USI. The 1–3–5 CST demonstrated excellent agreement with urodynamic severity (overall concordance 81.7%), with perfect identification of mild cases and high accuracy for moderate (76.7%) and severe SUI (78.6%). ICIQ-UI-SF scores increased with severity (mean 6.29 in mild, 13.65 in moderate, and 14.21 in severe USI). Similarly, ICIQ-FLUTS scores were lower in mild cases (mean 10.10) compared to moderate (18.21) and severe USI (18.23), with no meaningful distinction between moderate and severe groups.The 1-hour pad test values were markedly lower in mild USI (mean 1.56 g) compared to moderate (16.78 g) and severe cases (18.44 g) (Table 2).
For ROC analysis, patients were dichotomized into mild versus moderate/severe USI. The 1–3–5 CST showed excellent diagnostic performance (AUC 0.99), with sensitivity 98.0% and specificity 100%. The ICIQ-UI-SF also demonstrated excellent performance (AUC 0.98), with high sensitivity (98.9%) and specificity (88.9%) (cut-off <6 for mild SUI). The 1-hour pad test showed very good performance (AUC 0.93), with lower sensitivity (51.5%) but excellent specificity (100%) (Table 3).

All non-invasive methods were effective in distinguishing mild from clinically significant SUI. However, questionnaires and pad testing demonstrated limited ability to differentiate between moderate and severe disease. The 1–3–5 CST showed the closest agreement with urodynamic findings and the most balanced diagnostic performance.These findings are consistent with existing literature, where the 1-hour pad test has inherent limitations, while the 1–3–5 CST and questionnaires more reliably reflect clinical continence status.[3] A limitation of this study is that, by using urodynamic USI as the reference standard, diagnostic performance could not be assessed in patients without demonstrable leakage during urodynamics.

The 1–3–5 CST appears to be the most reliable non-invasive method for assessing SUI severity, closely reflecting urodynamic findings. Patient-reported outcome measures and pad testing are useful for identifying clinically significant SUI but have limited value in grading higher severity levels. These findings support the role of the 1–3–5 CST as an effective tool in the evaluation of SUI severity.

1.	Mikos T, Theodoulidis I, Karalis T, Zafrakas M, Grimbizis GF. Instruments used for the assessment of stress urinary incontinence severity in urogynecologic surgical trials: a scoping review. Int Urogynecol J. 2024;35:2255–2279.
2.	Guralnick ML, Fritel X, Tarcan T, Espuna-Pons M, Rosier PFWM. ICS Educational Module: Cough stress test in the evaluation of female urinary incontinence: Introducing the ICS-Uniform Cough Stress Test. Neurourol Urodyn. 2018;37:1849–1855
3.	Grigoriadis T, Giannoulis G, Zacharakis D, Protopapas A, Cardozo L, Athanasiou S. The “1–3–5 cough test”: comparing the severity of urodynamic stress incontinence with severity measures of subjective perception of stress urinary incontinence. Int Urogynecol J. 2015;26(10):1515–1521.