title: Diagnostic accuracy of real-time polymerase chain reaction in detection of Clostridium difficile in the stool samples of patients with suspected Clostridium difficile Infection: a meta-analysis.
abstract: BACKGROUND
  Current detection methods for Clostridium difficile infection (CDI) can be time-consuming and have variable sensitivities. Real-time polymerase chain reaction (PCR) may allow earlier and more accurate diagnosis of CDI than other currently available diagnostic tests. A meta-analysis was performed to determine the diagnostic accuracy of real-time PCR.
  
  
  METHODS
  We searched MEDLINE (Pubmed/Ovid) and 4 other online electronic databases (1995-2010) to identify diagnostic accuracy studies that compared PCR with cell culture cytotoxicity neutralization assay (CCCNA) or anaerobic toxigenic culture (TC) of C. difficile. Screening for inclusion, data extraction, and quality assessment were carried out independently by 2 investigators and disagreements resolved. Data were combined by means of a random-effects model, and summary receiver operating characteristic curves and diagnostic odds ratios were calculated.
  
  
  RESULTS
  Nineteen studies (7392 samples) met our inclusion criteria. The overall mean sensitivity of PCR was 90% (95% confidence interval [CI]: 88%-91%), specificity 96% (CI: 96%-97%), positive likelihood ratio 26.89 (CI: 20.81-34.74), negative likelihood ratio 0.11 (CI: .08-.15), diagnostic odds ratio 278.23 (CI: 213.56-362.50), and area under the curve 0.98 (CI: .98-.99). Test accuracy depended on the prevalence of C. difficile but not on the reference test used. At C. difficile prevalence of <10%, 10%-20% and >20% the positive predictive value and the negative predictive value were 71%, 79%, 93% and 99%, 98% and 96%, respectively.
  
  
  CONCLUSIONS
  Real-time PCR has a high sensitivity and specificity to confirm CDI. Overall diagnostic accuracy is variable and depends on CDI prevalence.
authors: Department of Neurological Surgery, Neurological Institute, Neurological Institute, Desk S60, 9500 Euclid Ave, Cleveland Clinic, Cleveland, OH. USA. deshpaa@ccf.org
authors: Abhishek
authors: A
authors: Deshpande
authors: Vinay
authors: V
authors: Pasupuleti
authors: David D K
authors: DD
authors: Rolston
authors: Anil
authors: A
authors: Jain
authors: Narayan
authors: N
authors: Deshpande
authors: Chaitanya
authors: C
authors: Pant
authors: Adrian V
authors: AV
authors: Hernandez
mesh_terms: D001431:Bacteriological Techniques / Q000379:methods*; D016360:Clostridioides difficile / Q000302:isolation & purification*; D003015:Clostridium Infections / Q000175:diagnosis* / Q000382:microbiology; D005243:Feces / Q000382:microbiology*; D006801:Humans; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity