1. Division of Surgery, Department of Clinical Science, Intervention, and Technology; Karolinska Institutet; Stockholm Sweden
2. Section of Upper Gastrointestinal Surgery, Centre of Gastrointestinal Disease; Karolinska University Hospital; Stockholm Sweden
3. Department of Clinical Science and Education; Södersjukhuset; Stockholm Sweden
4. Department of Medical Epidemiology and Biostatistics; Karolinska Institutet; Sweden
5. Institute of Environmental Medicine; Karolinska Institutet; Stockholm Sweden