Introduction Colorectal cancer (CRC) screening programmes can reduce incidence and mortality from this condition if adherence to them is high. As patient experience and satisfaction are key factors in determining adherence to screening programmes, they need to be measured. Furthermore, to promote highly patient-centred healthcare, the perception of patients regarding shared decision-making during CRC screening needs to be known. This study aims to assess the experience, satisfaction and participation in decision-making of participants in a CRC screening programme and of patients diagnosed with CRC through this programme in relation to the diagnostic and therapeutic processes of cancer.Methods and analysis The CyDESA study is a mixed-methods study with a four phase sequential design. In phase 1, we will conduct a systematic review of patient-reported experience measures (PREMs) for patient experience or satisfaction with CRC screening. In case no located PREM can be applied, in phase 2, we will develop a new PREM. We will use the Delphi methodology to reach consensus among experts and patients and will conduct a pilot test of the developed PREM. Phase 3 is a multicentric cross-sectional study based on self-reported questionnaires that will be conducted at three Spanish hospitals (n=843). The objective is to find out about the experience, satisfaction and participation in decision-making of participants in the CRC screening programme who have had a positive screening test result according to their final screening diagnosis: false positives, colorectal polyps or CRC. Phase 4 is a qualitative phenomenological study based on individual interviews. It will explore the experiences of participants in the CRC screening programme and of those diagnosed with CRC.Ethics and dissemination Ethics approval by the Ethics Committees of Corporació Sanitària Parc Taulí, Hospital de Sant Pau and Parc de Salut Mar. Findings will be published in peer-reviewed journals and presented at conferences.Trial registration number NCT04610086.
