The Gothenburg study of perioperative risk. I. Preoperative findings, postoperative complications

The Gothenburg study of Perioperative Risk is a prospective clinical-epidemiological study designed to elucidate factors affecting the perioperative risk in unselected adult patients undergoing elective general or orthopaedic surgery. In this report reference data regarding preoperative characteristics and postoperative complications are presented. 1770 adult patients scheduled for elective general, urological, peripheral vascular or orthopaedic operative procedures were invited to a preoperative clinic. 81% agreed to participate and were assessed in a standardised way by means of questionnaires, interview, physical examination and laboratory screening. 82% had a previous or present condition in the medical history of some concern to the assessor. 71% had a finding of significance on physical examination. In 8% the assessment prompted further investigations or precautions. Throughout their hospital stay, all the 1361 participating patients were visited daily by an especially trained nurse with the task of registering the occurrence of complications. In 30% an untoward event occurred postoperatively--in 1% a severe one, in 21% a mild event, and in 8% an intermediate one. The complication rate was higher in vascular surgery (69%) than in orthopaedic (33%) and general/urological surgery (26%). Not only the severe and intermediate but also the mild complications affected the number of days in hospital.