The methodology employed is included in the following document: “Preparation of Clinical Practice Guidelines in the National Health System. Methodology Manual”, from the Ministry of Health and Consumer Affairs and the Aragon Institute of Health Science¹⁴.

The steps to be followed are:

1. Forming the guidelines preparation group, composed of specialists in urology, radiotherapy, medical oncology and pathology, nursing in urology and methodologists.
2. Formulation of clinical questions using the format: Patient/intervention/comparison/outcome or PICO.
3. Bibliographic Search in: The Cochrane Library, DARE, Medline-PubMed, Embase, Trip Database, IME and manual search. Languages of studies elected: English, French, Italian, Portuguese and Spanish. As a first phase, a preliminary search of the CPG and systematic reviews was carried out. Two CPGs on prostate cancer were identified which were rated with the instrument AGREE²⁰. One was then chosen^16,17 17 as a secondary source of evidence to help with specific sections in the guide, according to the methodology of preparation-adaptation-update used in the Basque Country clinical practice guide on asthma²¹. As a second phase, an extended search of original studies (controlled and randomised clinical trials, observational, prognostic and case series studies) was carried out.
4. Evaluating the quality of the studies and a summary of the evidence for each question, following the SIGN recommendations (Scottish Intercollegiate Guidelines Network)²².
5. Preparing recommendations based on "formal evaluation" or "reasoned judgment" in SIGN. The classification of evidence and the grading of the recommendations was done with the SIGN system (see Appendix 1)²². Controversial recommendations or those with an absence of evidence were resolved by consensus during several meetings of the preparation group.
6. Expert collaborators participated in the revision and drafting of the recommendations and the external reviewers supplied notable contributions to the draft guidelines revision.
7. Collaboration from the following scientific organisations was received: the Spanish Association of Urology (AEU), Spanish Society of Radiotherapeutic Oncology (SEOR), Spanish Society of Medical Oncology (SEOM) and the Spanish Association of Nursing in Urology (AEEU), who were represented by members of the preparation group, the expert collaborators and the external reviewers.
8. The detailed information with the CPG methodological process is available at http://www.guiasalud.es.

An update is planned for the guide every three years, or less if new scientific evidence (that could modify some of the recommendations offered in this guide) appears. Updates will be made on the electronic version of the guide, available at http://www.guiasalud.es.