[1] Karlstad Hosp, Dept Surg, Karlstad, Sweden
[2] Univ Gothenburg, Sahlgrenska Acad, Inst Clin Sci, Dept Surg,SSORG Scandinavian Surg Outcomes Res Gr, Gothenburg, Sweden
[3] Reg Vastra Gotaland, Sahlgrenska Univ Hosp, Dept Surg, Gothenburg, Sweden
[4] Orebro Univ, Fac Med & Hlth, Dept Surg, Orebro, Sweden
[5] Univ Copenhagen, Herlev Hosp, Dept Surg, Herlev, Denmark