title: Matching criteria in case-control studies in the field of antimicrobial resistance.
abstract: OBJECTIVE
  We evaluated the available evidence from case-control studies in the field of antimicrobial resistance to identify the degree that matching was performed and the criteria used to do so.
  
  
  METHODS
  We performed a systematic search of the PubMed database (articles archived by 08/2006) to identify relevant studies. Studies that used the individual matching technique were further analyzed.
  
  
  RESULTS
  115 case-control studies with a focus on antimicrobial resistance were identified: 28 regarding Acinetobacter baumannii, 25 regarding Pseudomonas aeruginosa, and 62 for other bacteria. Individual matching was performed in 32 (27.8%) out of the 115 studies. Age was the most frequently used matching criterion in 22 of 32 (69%) evaluated matched case-control studies, while sex was used in 11 (34%), presence of underlying illness in 8 (25%), site of infection in 5 (16%), and area of residence in 4 studies (12.5%). Other criteria were used in less than 10% of the studies. Analysis of data for matched pairs was performed in 18 of 32 (56.3%) studies that used a matched case-control design.
  
  
  CONCLUSIONS
  The available evidence from the analyzed data from case-control studies in the field of antimicrobial resistance shows that individual matching is employed only in a proportion of such studies and only for a few characteristics, when it was used. Also, analysis for matched pairs was not used by almost a half of the relevant studies.
authors.affiliation: Alfa Institute of Biomedical Sciences, Athens, Greece. m.falagas@aibs.gr
authors.forename: Matthew E
authors.initials: ME
authors.lastname: Falagas
authors.forename: Eleni G
authors.initials: EG
authors.lastname: Mourtzoukou
authors.forename: Konstantina P
authors.initials: KP
authors.lastname: Giannopoulou
authors.forename: Vangelis G
authors.initials: VG
authors.lastname: Alexiou
authors.forename: Petros I
authors.initials: PI
authors.lastname: Rafailidis
mesh_terms: D040981:Acinetobacter baumannii / Q000187:drug effects*; D000367:Age Factors; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001419:Bacteria / Q000145:classification / Q000187:drug effects; D001424:Bacterial Infections / Q000382:microbiology; D016022:Case-Control Studies; D024901:Drug Resistance, Multiple, Bacterial; D006801:Humans; D016555:Matched-Pair Analysis; D011550:Pseudomonas aeruginosa / Q000187:drug effects*; D012307:Risk Factors; D012737:Sex Factors
chemical_list: D000900:Anti-Bacterial Agents