Journal article
Impact of severity of illness bias and control group misclassification bias in case-control studies of antimicrobial-resistant organisms
Infection control and hospital epidemiology, Vol.26(4), pp.342-345
04/2005
DOI: 10.1086/502549
PMID: 15865268
Abstract
Case-control studies often analyze risk factors for antibiotic resistance. Recently published articles have illustrated that randomly selected control-patients may be preferable to those with the susceptible phenotype of the organism. A possible methodologic problem with randomly selected control-patients is potential bias due to control group misclassification. This occurs if some control-patients did not have clinical cultures performed and thus might have been unidentified case-patients. If this bias exists, these studies might be expected to report lower odds ratios (ORs) because control-patients would be more like case-patients. To analyze potential biases that might arise due to control group misclassification and potentially larger selection biases that may be introduced if control-patients are required to have at least one clinical culture. One hundred twenty case-patients, 770 control-patients in group 1, and 510 control-patients in group 2. Two case-control studies. Case-patients had clinical cultures positive for imipenem-resistant Pseudomonas aeruginosa. The first group of control-patients were random. The second group of control-patients were identical to those in group 1 except being required to have at least one clinical culture. Univariate analyses showed higher ORs for case-patients versus control-patients in group 1 (imipenem [OR, 12.5], piperacillin-tazobactam [OR, 3.7], and vancomycin [OR, 4.7]) as compared with case-patients versus control-patients in group 2 (imipenem [OR, 8.0], piperacillin-tazobactam [OR, 2.5], and vancomycin [OR, 3.0]). Requiring control-patients to have at least one clinical culture introduces a selection bias likely because it eliminates patients with less severe illness.
Details
- Title: Subtitle
- Impact of severity of illness bias and control group misclassification bias in case-control studies of antimicrobial-resistant organisms
- Creators
- Anthony D Harris - Department of Epidemiology and Preventive Medicine, University of Maryland, College Park, USA. aharris@epi.umaryland.eduYehuda CarmeliMatthew H SamoreKeith S KayeEli Perencevich
- Resource Type
- Journal article
- Publication Details
- Infection control and hospital epidemiology, Vol.26(4), pp.342-345
- Publisher
- United States
- DOI
- 10.1086/502549
- PMID
- 15865268
- ISSN
- 0899-823X
- eISSN
- 1559-6834
- Grant note
- K23 AI01752-01A1 / NIAID NIH HHS
- Language
- English
- Date published
- 04/2005
- Academic Unit
- Epidemiology; Internal Medicine
- Record Identifier
- 9983779497302771
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