2. METHODS
2.1. Data Identification
For the 2025 NMIBC Guidelines, new and relevant evidence has been identified, collated, and appraised through a structured assessment of the literature. A broad and comprehensive scoping exercise covering all areas of the NMIBC Guidelines was performed. Databases searched included Medline, EMBASE, and the Cochrane Libraries, covering a time frame between the 1st May 2023 and 1st May 2024. A total of 743 unique records were identified, retrieved, and screened for relevance. A total of 36 new references were added to the 2025 NMIBC Guidelines. A detailed search strategy is available online: https://uroweb.org/guidelines/non-muscle-invasive-bladder-cancer/publications-appendices.
For chapters 3 through 6 (Epidemiology, Aetiology and Pathology, Staging and Classification systems, Diagnosis, Predicting disease recurrence and progression) the references used in this text were assessed according to their level of evidence (LE) based on the 2009 Oxford Centre for Evidence-Based Medicine (CEBM) Levels of Evidence [5]. For chapters 7 and 8 (Disease Management and Follow-up) chapters a system modified from the 2009 CEBM levels of evidence was used [5].
Recommendations within the Guidelines are developed by the panels to prioritise clinically important care decisions. The strength of each recommendation is determined by the balance between desirable and undesirable consequences of alternative management strategies, the quality of the evidence (including certainty of estimates), and the nature and variability of patient values and preferences. This decision process, which can be reviewed in the strength rating forms which accompany each guideline statement, addresses a number of key elements:
- the overall quality of the evidence which exists for the recommendation [5];
- the magnitude of the effect (individual or combined effects);
- the certainty of the results (precision, consistency, heterogeneity and other statistical or study related factors);
- the balance between desirable and undesirable outcomes;
- the impact and certainty of patient values and preferences on the intervention.
Strong recommendations typically indicate a high degree of evidence quality and / or a favourable balance of benefit to harm and patient preference. Weak recommendations typically indicate availability of lower quality evidence, and/or equivocal balance between benefit and harm, and uncertainty or variability of patient preference [6].
Additional methodology information and a list of associations endorsing the EAU Guidelines can be found online: https://uroweb.org/eau-guidelines/methodology-policies.
2.2. Review
The 2024 publication was peer reviewed prior to publication.
2.3. Future goals
The Panel are currently conducting two individual patient data (IPD) analyses to validate the definition of bacillus Calmette-Guérin (BCG) failure/BCG unresponsive in patients with non-muscle invasive urothelial carcinoma of the bladder and the impact of BCG on progression in the BCG treated subgroup of the original cohort that served to generate the 2021 risk stratification. The results of both analyses will be included in the future update of the NMIBC Guidelines.