There is growing concern that neckties worn by health care professionals may contribute to infections contracted in health care settings. We evaluated the evidence for health-care-associated infections resulting from neckties and whether the evidence is sufficient to warrant a tieless policy in Canada. We performed a systematic review to determine whether neckties worn by health care professionals colonize harmful pathogenic bacteria and whether they contribute to the spread of infection to patients in the inpatient or outpatient setting. We searched PubMed (1966 to 2017) and Embase (1974 to 2017). The level of evidence was appraised according to the Oxford Centre for Evidence-Based Medicine levels of evidence. We evaluated the quality of evidence and the risk of bias using the Jadad scale or the Newcastle-Ottawa Scale. We screened 1675 citations, of which 6 were ultimately included in the systematic review. Only 1 study gave level 1b evidence (randomized controlled trial). Neckties were more likely than shirt pockets to colonize bacteria. There is limited evidence that neckties may be contaminated with pathogenic bacteria (e.g., methicillin-resistant Staphylococcus aureus) and very limited evidence that contaminated neckties may transmit bacteria (in a controlled experimental setting to a mannequin). There is no evidence of increased rates of health-care-associated infections related to the wearing of neckties by health care professionals. There is weak evidence that neckties are contaminated with pathogenic (and nonpathogenic) bacteria. The level of evidence was weak and the studies were heterogeneous. Evidence to support the need for a tieless dress code policy is lacking. Only 1 study gave level 1b evidence (randomized controlled trial). Neckties were more likely than shirt pockets to colonize bacteria. There is limited evidence that neckties may be contaminated with pathogenic bacteria (e.g., methicillin-resistant Staphylococcus aureus ) and very limited evidence that contaminated neckties may transmit bacteria (in a controlled experimental setting to a mannequin). Interpretation: There is no evidence of increased rates of health-care-associated infections related to the wearing of neckties by health care professionals. There is weak evidence that neckties are contaminated with pathogenic (and nonpathogenic) bacteria. 4 This policy has since become known as the "bare-below-the-elbow" attire policy as a means for reducing the spread of nosocomial infections. It was recommended that National Health Service staff wear short sleeves and avoid unnecessary jewellery and garments such as neckties when carrying out clinical activities. 4 No evidence was cited to support the recommendation against the wearing of ties. If the wearing of neckties increases the risk of health care-associated infections, such a policy restricting their use by health care professionals in Canada (and elsewhere) would be warranted. There is very limited evidence that neckties may be contaminated more often with pathogenic bacteria (e.g., MRSA) and that contaminated neckties transmit bacteria in a controlled experimental setting (to a mannequin). Despite this, there is evidence neither that a health care professional who wears a necktie is responsible for increased rates of health-care-associated infections nor that restricting health care professionals from wearing neckties will decrease the rate of occurrence of such infections. Rehman and colleagues 25 found that 76.3% of patients preferred their physician to be clothed in professional attire, i.e., shirt, necktie and white coat for male physicians, and tailored trouser or skirt with white coat for female physicians. Respondents' trust, confidence and willingness to share personal information were greater for a physician in professional attire. Hence, recommendations against the wearing of a The data available in the literature were heterogeneous and were evaluated qualitatively by validated methods versus quantitatively through meta-analysis. Second, our literature search set limits to articles published in English. However, none of the references cited in the bare-below-the-elbow policy study 4 were in languages other than English, and, in general, exclusion of non-English-language articles has been found not to have a significant impact on the results of systematic reviews. 26 Conclusion There is a lack of evidence to suggest that the wearing of neckties by health care professionals contributes to a higher rate of health-care-associated infections. The wearing of a necktie by a health care professional is a symbol evoking trust and confidence for a patient. Simple measures to avoid patient contact by the necktie seem prudent, but the available evidence does not support a nation-wide policy restricting their use. However, the data are sparse. If concerns remain regarding the wearing of neckties, a larger prospective study is required before a nation-wide policy against their use is implemented in Canada. Supplemental information For reviewer comments and the original submission of this manuscript, please see www.cmajopen.ca/content/6/1/E26/suppl/DC1. Close Citation Tools Citation Tools Health care professionals' neckties as a source of transmission of bacteria to patients: a systematic review Pia Pace-Asciak Pia Pace-Asciak Sanjiv K. Bhimrao Sanjiv K. Bhimrao Frederick K. Kozak Frederick K. Kozak and Brian D. Westerberg Brian D. Westerberg Canadian Medical Association Open Access Journal Jan 2018, 6 (1) E26-E30; DOI: 10.9778/cmajo.20170126 Citation Manager Formats BibTeX Bookends EasyBib EndNote (tagged) EndNote 8 (xml) Medlars Mendeley Papers RefWorks Tagged Ref Manager RIS Zotero Share Share This Article Health care professionals' neckties as a source of transmission of bacteria to patients: a systematic review Pia Pace-Asciak Pia Pace-Asciak Sanjiv K. Bhimrao Sanjiv K. Bhimrao Frederick K. Kozak Frederick K. Kozak and Brian D. Westerberg Brian D.