The quality of measurement of surgical wound infection as the basis for monitoring: a systematic review

Comparison of postoperative surgical wound infection rates between institut ions and over time is only valid if standard, valid and reliable definition s are used. The aim of this review was to assess evidence of validity and r eliability of the definition and measurement of surgical wound infection. A systematic review was undertaken of prospective studies of surgical wound infection published over a seven-year period; 1993-1999. The information ex tracted from individual studies included: definition of surgical wound infe ction; details of wound assessment scale, scoring or grading scale systems; and evidence of assessment of validity, reliability and feasibility of ide ntified definitions and grading systems. Two independent reviewers appraise d 112 prospective studies, 90 of which were eligible for inclusion; eight s tudies assessed validity and/or reliability. Forty-one different definition s of surgical wound infection were identified, five of which were 'standard ' definitions proposed by multi-disciplinary groups. Presence of pus was th e most frequently used single component of any definition; the CDC definiti ons of 1988 and 1992 were the most widely implemented standard definitions; and the ASEPSIS wound assessment scale was the most frequently used quanti tative grading tool. Only two formal validations of a definition were found , and six studies of reliability. This review highlights the extent of vari ation in definition of surgical wound infection used in clinical practice, and the need for validation of both content and organization of a surveilla nce system. However, realistically, there will have to be a balance between the quality of the measurement and the practicality of surveillance. (C) 2 001 The Hospital Infection Society.