The use of polyacrylamide hydrogel (PAH) for treating female stress urinary incontinence (SUI) has significantly increased in Norway in recent years. This rise is largely due to its lower complication risk compared to synthetic and autologous fascial slings, as well as its ability to be performed under local anesthesia in an outpatient setting. The primary aim of this study was to identify predictors of subjective cure at the 6-12 month follow-up after PAH treatment, thereby providing better preoperative guidance for women considering PAH as an alternative to more invasive treatments, which carry a potentially higher risk of complications.

We analyzed data from the mandatory Norwegian Female Incontinence Registry (NFIR) covering the period from 2014 to 2022. All women who underwent PAH treatment during this timeframe were included. Follow-up data collected between 6 and 12 months post-treatment were extracted through 2024. Hospitals were categorized based on their annual volume of PAH procedures: small (<30), medium (30–99), and large (≥100). Preoperative and 6-12 months postoperative assessments included subjective data from a validated NFIR symptom questionnaire, as well as objective results from a cough/jump pad-weighing stress test, urinary flow measurements, and post-void residual volumes. The NFIR questionnaire evaluates symptom burden for both stress and urgency urinary incontinence by calculating a stress index (0–12) and an urgency index (0–8), with higher scores indicating more severe symptoms. Subjective cure was defined as a follow-up stress index <3, signifying minimal or no symptoms. Multivariate logistic regression analysis was employed to identify predictors.

A total of 1527 women who received PAH injection therapy were registered in the NFIR between 2014 and 2022. The results are summarized in Table 1. The group reporting subjective cure was older (mean age: 58.8 vs. 54.4 years, p < 0.001), had less preoperative objective leakage (28.2 g vs. 35.2 g, p = 0.014), and fewer SUI symptoms (stress index: 7.7 vs. 8.1, p < 0.001). Hospital size, preoperative post-void residuals, maximum flow, and leakage during intercourse were not significantly associated with subjective cure in the multivariate logistic regression model.

Injection therapy may be particularly suitable for older patients and those with milder SUI, as measured by either symptom scores (lower stress index) or objective testing (less leakage on the cough/jump stress test). Younger women with more severe symptoms should be informed that they are likely to benefit more from more invasive treatments, such as synthetic or fascial slings. However, these more invasive treatments carry a higher risk of complications. This information can help both women and clinicians tailor treatment strategies to meet the specific needs of individual patients.

This study identifies potential predictors of subjective cure following polyacrylamide hydrogel (PAH) injection therapy for SUI. Older patients, those with less severe symptoms, and those with less objective leakage on the cough/jump stress test were more likely to achieve subjective cure. These findings support the use of tailored treatment approaches based on patient characteristics.