About the Authors
Department of Surgery, University Hospital of Uppsala and Regional Oncologic Centre, Uppsala, Sweden
Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
Department of Surgery, Centre for Clinical Research, Central Hospital of Västerås, Västerås, Sweden
The authors have declared that no competing interests exist.
SE performed all of the analyses, contributed to the interpretation of the data, and drafted the article. PWD contributed with the analysis and interpretation of the data. LB contributed with the acquisition of the data, with detailed knowledge about the register, and with revising the article for intellectual content. LH contributed with the conception and the design of the study, interpretation of the data, and revising the article for intellectual content.