This document is Deliverable 5.1 (“Protocols of mixed-methods study on sociocultural, economic, and behavioural factors”) of the CANCER PREVENTION AT WORK (CPW) project. It is issued under the responsibility of the University of Southern Denmark (SDU) with the contribution of a working group comprising principal investigators and team members from work packages WP2, WP3, and W4, as well as the project coordinator Prof. Dr. Paolo Boffetta and the project manager Alessandra Cataneo from the University of Bologna. The objective of WP5 is to identify, assess, and address the behavioural and sociocultural barriers and facilitators of the interventions against infection-related cancers conducted in WP2-WP4. In particular, we aim to do so by identifying the barriers and facilitators of the primary prevention interventions in this project through a mixed methods study. As a part of this study, we collect: • secondary data through a review of extant literature on sociocultural, economic, and behavioural barriers and facilitators of cancer prevention, • primary mixed quantitative/qualitative data through the baseline questionnaires of the involved workplace and occupational cohorts, and • primary qualitative data through focus groups with individuals from a subset of the workplace and occupational cohorts. This study represents the first phase in a multi-phased overall study design, which is similar to one that has been successfully employed in a large study on under- and never-screened populations in the context of breast, cervical, and colorectal cancer.1 Special care is taken to facilitate the geographically and culturally dispersed data collection. Through the study described in deliverable D5.1, we aim to build a solid understanding of the sociocultural, economic, and behavioural factors influencing patterns of participation and nonparticipation in screening examinations (WP2 & WP3), patterns of hesitancy to vaccination interventions (WP4), and the patient pathways in case of positive screening results (WP2 & WP3).