The scientific evidence for a potential link between confusion and urinary tract infection in the elderly is still confusing - a systematic literature review

Mayne, Sean, Bowden, Alexander, Sundvall, Pär-Daniel, and Gunnarsson, Ronny (2019) The scientific evidence for a potential link between confusion and urinary tract infection in the elderly is still confusing - a systematic literature review. BMC Geriatrics, 19. 32.

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Background: Non-specific symptoms, such as confusion, are often suspected to be caused by urinary tract infection (UTI) and continues to be the most common reason for suspecting a UTI despite many other potential causes. This leads to significant overdiagnosis of UTI, inappropriate antibiotic use and potential harmful outcomes. This problem is particularly prevalent in nursing home settings.

Methods: A systematic review of the literature was conducted assessing the association between confusion and UTI in the elderly. PubMed, Scopus and PsychInfo were searched with the following terms: confusion, delirium, altered mental status, acute confusional state, urinary tract infection, urine infection, urinary infection and bacteriuria. Inclusion criteria and methods were specified in advance and documented in the protocol, which was published with PROSPERO (registration ID: CRD42015025804). Quality assessment was conducted independently by two authors. Data were extracted using a standardised extraction tool and a qualitative synthesis of evidence was made.

Results: One thousand seven hunderd two original records were identified, of which 22 were included in the final analysis. The quality of these included studies varied, with frequent poor case definitions for UTI or confusion contributing to large variation in results and limiting their validity. Eight studies defined confusion using valid criteria; however, no studies defined UTI in accordance with established criteria. As no study used an acceptable definition of confusion and UTI, an association could not be reliably established. Only one study had acceptable definitions of confusion and bacteriuria, reporting an association with the relative risk being 1.4 (95% CI 1.0-1.7, p = 0.034).

Conclusions: Current evidence appears insufficient to accurately determine if UTI and confusion are associated, with estimates varying widely. This was often attributable to poor case definitions for UTI or confusion, or inadequate control of confounding factors. Future well-designed studies, using validated criteria for UTI and confusion are required to examine the relationship between UTI and acute confusion in the elderly. The optimal solution to clarify this clinical issue would be a randomized controlled trial comparing the effect of antibiotics versus placebo in patients with new onset or worsening confusion and presence of bacteriuria while lacking specific urinary tract symptoms.

Item ID: 61879
Item Type: Article (Research - C1)
ISSN: 1471-2318
Keywords: Bacteriuria, Confusion, Delirium, Elderly, Urinary tract infection
Copyright Information: © 2019 The Author(s). Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.
Funders: James Cook University (JCU)
Projects and Grants: JCU College of Medicine and Dentistry
Date Deposited: 18 May 2020 23:03
FoR Codes: 52 PSYCHOLOGY > 5201 Applied and developmental psychology > 520106 Psychology of ageing @ 50%
42 HEALTH SCIENCES > 4203 Health services and systems > 420301 Aged health care @ 50%
SEO Codes: 92 HEALTH > 9201 Clinical Health (Organs, Diseases and Abnormal Conditions) > 920119 Urogenital System and Disorders @ 50%
92 HEALTH > 9205 Specific Population Health (excl. Indigenous Health) > 920502 Health Related to Ageing @ 50%
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