title: C-reactive protein has a better discriminative power than white cell count in the diagnosis of acute cholecystitis.
abstract: BACKGROUND
  The diagnosis of acute cholecystitis (AC) is challenging and may result in a delay in surgery, hospital discharge, and increased mortality. To improve its diagnosis, C-reactive protein (CRP) has been proposed as a benchmark. The aim of this study was to evaluate discriminative power of CRP against white cell count (WCC) in AC.
  
  
  METHODS
  This was a retrospective cohort study. Over a 5-y period, 1959 patients were identified from the audit of cholecystectomies. The exclusion criteria were coexisting acute surgical conditions, absence of blood tests within 3 d before hospital admission for elective surgery, and private patients.
  
  
  RESULTS
  The eligibility criteria were met by 1843 patients. Comparison of the area under receiver operating characteristic (AUC) curve of CRP and WCC in acute on chronic, edematous, necrotic, suppurative, and gangrenous AC showed a better discriminative power of CRP. Both tests performed equally well in patients with pericholecystic abscess and gallbladder perforation. CRP was superior than WCC in mild AC, AUC = 0.93 (95% confidence interval [CI], 0.9-0.95) and 0.79 (95% CI, 0.74-0.84), P < 0.00005, in moderate and severe AC, AUC = 0.99 (95% CI, 0.97-1.0) and 0.92 (95% CI, 0.88-0.97), P = 0.009, and in all forms of AC combined, AUC = 0.94; (95% CI, 0.92-0.97) and 0.83 (95% CI, 0.79-0.87), respectively, P < 0.00005.
  
  
  CONCLUSIONS
  CRP has a better discriminative power than WCC in most forms of AC and is a useful diagnostic marker of AC.
authors.affiliation: Department of Surgery, Auckland City Hospital, Auckland, New Zealand. Electronic address: AndreiB@adhb.govt.nz.
authors.forename: Andrei M
authors.initials: AM
authors.lastname: Beliaev
authors.affiliation: Department of Epidemiology and Statistics, University of Auckland, Auckland, New Zealand.
authors.forename: Roger J
authors.initials: RJ
authors.lastname: Marshall
authors.affiliation: Department of General Surgery, North Shore Hospital, Auckland, New Zealand.
authors.forename: Michael
authors.initials: M
authors.lastname: Booth
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D002097:C-Reactive Protein / Q000032:analysis*; D041881:Cholecystitis, Acute / Q000097:blood / Q000175:diagnosis*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
chemical_list: D002097:C-Reactive Protein
keywords: Acute cholecystitis; CRP; Diagnosis; WCC