Footnotes

• Contributors All the authors fulfilled the ICMJE four authorship criteria. There is no one else who fulfils the criteria that has been excluded as an author. All authors gave permission to be included. OS is responsible for the overall content as guarantor. The guarantor accepts full responsibility for this work. OS: planned the study, organised data collection, interpreted the results, drafted the manuscript. RV: gathered data, conducted the data analysis, interpreted the results, drafted the results. EL: conducted data collection. IP: conducted data statistical analysis and interpretation. DP: gathered data, conducted data analysis. KC: gathered data, conducted data analysis, interpreted the results. AJ: communication with the respondents, data collection. SP: organised data storage, data analysis, IT support for data storage. IS: organised the study performance, managed the organisation of the research process. JYP: drafted the manuscript and edited it for clarity, style and grammar. LE: interpreted data and edited it for clarity. ML: designed the study methodology and developed data collection and analysis plan, formulated the research questions, edited the drafted manuscript.

• Funding The study was supported by the ERDF (European Regional Development Fund) in Latvia, project No. 1.1.1.1/18/A/184 'Optimisation of H. pylori eradication therapy for population-based gastric cancer prevention'.

• Disclaimer Where authors are identified as personnel of the International Agency for Research on Cancer/WHO, the authors alone are responsible for the views expressed in this article, and they do not necessarily represent the decisions, policy or views of the International Agency for Research on Cancer/WHO.

• Competing interests None declared.

• Provenance and peer review Not commissioned; internally peer reviewed.

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