[1] Karolinska Inst, Dept Clin Sci & Educ, Sodersjukhuset, Stockholm, Sweden
[2] Sodertalje Hosp, Dept Surg, Sodertalje, Sweden
[3] Karolinska Inst, Dept Mol Med & Surg, Stockholm, Sweden
[4] Karolinska Inst, Ersta Hosp, Danderyd Hosp, Dept Surg,Dept Clin Sci, Stockholm, Sweden
[5] Karolinska Inst, Dept Med Solna, Clin Epidemiol Unit, Stockholm, Sweden