title: Systematic review and meta-analysis of use of serum C-reactive protein levels to predict anastomotic leak after colorectal surgery.
abstract: BACKGROUND
  Several recent studies have investigated the role of C-reactive protein (CRP) as an early marker of anastomotic leakage following colorectal surgery. The aim of this systematic review and meta-analysis was to evaluate the predictive value of CRP in this setting.
  
  
  METHODS
  A systematic literature search was performed using MEDLINE, Embase and PubMed to identify studies evaluating the diagnostic accuracy of postoperative CRP for anastomotic leakage following colorectal surgery. A meta-analysis was carried out using a random-effects model and pooled predictive parameters were determined along with a CRP cut-off value at each postoperative day (POD).
  
  
  RESULTS
  Seven studies, with a total of 2483 patients, were included. The pooled prevalence of leakage was 9·6 per cent and the median day on which leakage was diagnosed ranged from POD 6 to 9. The serum CRP level on POD 3, 4 and 5 had comparable diagnostic accuracy for the development of an anastomotic leak with a pooled area under the curve of 0·81 (95 per cent confidence interval 0·75 to 0·86), 0·80 (0·74 to 0·86) and 0·80 (0·73 to 0·87) respectively. The derived CRP cut-off values were 172 mg/l on POD 3, 124 mg/l on POD 4 and 144 mg/l on POD 5; these corresponded to a negative predictive value of 97 per cent and a negative likelihood ratio of 0·26-0·33. All three time points had a low positive predictive value for leakage, ranging between 21 and 23 per cent.
  
  
  CONCLUSIONS
  CRP is a useful negative predictive test for the development of anastomotic leakage following colorectal surgery.
authors: Department of Surgery, South Auckland Clinical School, Middlemore Hospital, University of Auckland, Auckland, New Zealand.
authors: P P
authors: PP
authors: Singh
authors: I S L
authors: IS
authors: Zeng
authors: S
authors: S
authors: Srinivasa
authors: D P
authors: DP
authors: Lemanu
authors: A B
authors: AB
authors: Connolly
authors: A G
authors: AG
authors: Hill
mesh_terms: D057868:Anastomotic Leak / Q000175:diagnosis*; D015415:Biomarkers / Q000378:metabolism; D002097:C-Reactive Protein / Q000378:metabolism*; D004812:Epidemiologic Methods; D006801:Humans; D011182:Postoperative Care; D012004:Rectal Neoplasms / Q000601:surgery*
chemical_list: D015415:Biomarkers; D002097:C-Reactive Protein