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

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.

Confusion Strongly Associated with Antibiotic Prescribing Due to Suspected Urinary Tract Infections in Nursing Homes.

OBJECTIVES: To quantify the prevalence of documented urinary tract infection (UTI), nonspecific symptoms, and antibiotic treatment of suspected UTI in nursing homes (NHs) in the tropics and to describe the typical resident likely to receive antibiotic treatment for suspected UTI and factors associated with the development of confusion, fatigue, and restlessness. DESIGN: Cross-sectional. SETTING: Five far north Queensland NHs in tropical Australia. PARTICIPANTS: NH residents (N = 450). MEASUREMENTS: Chart reviews of NH residents between August 28, 2015, and June 21, 2016, to determine the prevalence of documented UTI, new or worsening nonspecific and specific symptoms that are specific or nonspecific to the urinary tract, antibiotic use, medical conditions, and medication factors. RESULTS: UTI accounted for 33% of all current infections treated with antibiotics and 40% of all infections treated with antibiotics within the last 30 days. One in 5 NH residents had received antibiotics within the last 30 days, of which 45% were for UTI. The most significant factors independently associated with antibiotics for UTI were urinary catheter (OR = 13, 95% CI = 2.4-67, P = .003), urinary frequency (OR = 10, 95% CI = 2.2-47, P = .003), fever (OR = 10, 95% CI = 1.3-85, P = .028), new-onset hypotension (OR = 10, 95% CI = 1.4-73, P = .024), and confusion (OR = 8.9, 95% CI = 3.1-26, P < .001). Of these, confusion was the most prevalent factor in the population. CONCLUSION: UTI is commonly documented in NH residents, with new or worsening confusion being one of the strongest factors associated with antibiotic treatment for suspected UTI.