title: The impact of overcrowding on the bacterial contamination of blood cultures in the ED.
abstract: OBJECTIVE
  This study aims to determine the risk factors associated with the bacterial contamination of blood cultures among adults visiting the emergency department (ED).
  
  
  METHODS
  Clinical variables and medical records of adults with bacterial growth of blood cultures in the ED as well as the degree of ED crowding, between August 2007 and July 2008, were prospectively collected.
  
  
  RESULTS
  Of the 11 491 adults who underwent blood culture sampling, the medical records of 558 (4.86%) eligible patients with bacterial growth in their blood cultures were analyzed. Most patients (366, or 3.19%) had true bacteremia, whereas 192 (1.67%) were regarded as contaminated. In multivariate analyses, ED overcrowding (scoring was based on a National Emergency Department Overcrowding Study [NEDOCS] score ≥ 100 points) was independently associated with blood culture contamination (odds ratio [OR], 1.58; P = .04). In contrast, other medical comorbidities, such as liver cirrhosis (OR, 0.31; P = .02), thrombocytopenia (<100 000/mm(3); OR, 0.28; P = .002), or high serum levels of C-reactive protein (>100 mg/L; OR, 0.24; P < .001), were negatively associated with blood culture contamination. On further analysis of the 5 crowding categories as stratified by NEDOCS scores, which included not busy and busy (0-60 points), extremely busy but not overcrowded (60-100), overcrowded (100-140), severely overcrowded (140-180), and dangerously overcrowded (180-200), there was a strong correlation between blood culture contamination rates and the degrees of ED crowding (γ = 0.99, P < .001).
  
  
  CONCLUSIONS
  Emergency department overcrowding may have an adverse impact on the quality of clinical care, including increasing the risk of blood culture contamination.
authors.affiliation: Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan.
authors.forename: Ching-Chi
authors.initials: CC
authors.lastname: Lee
authors.forename: Nan-Yao
authors.initials: NY
authors.lastname: Lee
authors.forename: Ming-Che
authors.initials: MC
authors.lastname: Chuang
authors.forename: Po-Lin
authors.initials: PL
authors.lastname: Chen
authors.forename: Chia-Ming
authors.initials: CM
authors.lastname: Chang
authors.forename: Wen-Chien
authors.initials: WC
authors.lastname: Ko
mesh_terms: D000328:Adult; D000368:Aged; D016470:Bacteremia / Q000175:diagnosis / Q000382:microbiology; D001769:Blood / Q000382:microbiology*; D001800:Blood Specimen Collection / Q000009:adverse effects / Q000706:statistics & numerical data; D016009:Chi-Square Distribution; D003441:Crowding; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005189:False Positive Reactions; D005260:Female; D006094:Gram-Positive Bacteria / Q000378:metabolism; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies