The risk of developing a urinary tract infection (UTI) rises as people age. It is more common in postmenopausal women and older men with prostatic disease. The presence of an indwelling urinary catheter (IUC) increases the risk of catheter-associated urinary tract infection (CAUTI) and up to 50% of women in long-term care may have asymptomatic bacteriuria (ASB). Bloodstream infection (BSI) is a serious consequence of UTI and can result in significant morbidity and mortality. The inappropriate treatment of UTI in older people in long-term residential care is an important driver for antimicrobial resistance.
This realist synthesis draws together evidence from research and grey literature and from stakeholder contributions by residents and family carers, care home staff and managers, primary care clinicians, specialist practitioners and commissioners of care to inform how interventions to prevent and recognise UTI and CAUTI can be delivered effectively by staff working in care homes.
Aim and objectives
The aim of the realist synthesis is to produce evidence-informed theoretical explanations of which strategies are effective (or not) in preventing older people in care homes from acquiring UTI.
The objectives are to:
identify which interventions could be effective, the mechanisms by which these strategies work (or why they fail), for whom and under what circumstances
understand what needs to be in place for the implementation of programmes to support the prevention of UTI and its recurrence in older people with and without a urinary catheter living in care homes in the UK.
Background
Care homes in the UK provide long-term residential or nursing care for a range of people who are vulnerable and have health and social support needs, in particular the frail elderly. In 2022, there were 408,371 people living in care homes in the UK. The population was higher in England than in any other part of the UK.1 The number of registered care homes in the UK in 2022 was reported as 17,079, many of which were owned and managed by the independent sector.2 Care homes are licensed and regulated in each of the devolved nations and funding of places ranges from fully privately funded, a mix of private and local authority funding and full local authority funding.
The workforce in care homes is similarly diverse with few professionally qualified staff. In 2022, data from England illustrated the low numbers of healthcare professionals (HCPs) working in the health and social care sector.3 Around 80,000 (5%) of the 1.62 million adult social care workforce were regulated professionals, of which 32,000 (2%) were registered nurses, with most of these (30,000) working in residential care establishments.3 In addition, care homes face a high turnover of staff, with a turnover rate of 34% in a 12-month period among registered nurses.3 This combination of factors makes the care home sector a complex environment in which to co-ordinate and manage infections.
Research suggests that a high proportion of people living in care homes have a degree of frailty, but that a further 40% are at risk of becoming frail.4 Care and nursing home residents have varying degrees of frailty, including levels of immunocompromise (a reduced ability to fight infections and other diseases), which make them more vulnerable to adverse events such as infection and falls.
The knowledge and skills required to respond to and manage outbreaks of infection in care homes are compromised by the paucity of training opportunities and limited resources available. Although care is often under the supervision of a registered nurse, staff working in care homes are likely to have limited knowledge of infection prevention. For the majority of the unqualified care home workforce across the UK, basic training includes minimal content on infection prevention and control (IPC) underpinned by a Care Certificate for staff recruited in recent years.5 In addition, evidence suggests that leadership at both a strategic and operational level within care homes has a significant effect on the way that care is delivered.6
Urinary tract infection
Urinary tract infection is the most commonly diagnosed infection in older people. It is caused by the multiplication of micro-organisms within the urinary tract and can result in a number of clinical syndromes, including pyelonephritis, cystitis and urethritis. Infection can also spread to the bloodstream. Consequences of UTI can range from a mild self-limiting illness to severe sepsis with a mortality rate of 20–40%.7,8 Inadequate antimicrobial therapy significantly increases the risk of infection spreading to the bloodstream. Resistance to antibiotics normally used to treat UTI is now common in the UK, with 40% of uropathogens now resistant to trimethoprim.9 Older people who experience repeated episodes of UTI, and therefore frequent exposure to antibiotics, are at greater risk of acquiring resistant pathogen-associated BSI.10,11 UTI accounts for more than 50% of antibiotic prescriptions in long-term care settings.12
The incidence of UTI increases with age in both men and women and is highest among those living in long-term care facilities at 44–58 infections per 100 person-years at risk.8 Several factors predispose older people to UTI, including genitourinary tract disorders, increased susceptibility to ASB (bacteria in the urine), cognitive impairment and incontinence.12,13 Older people living in care homes are more likely to have these comorbidities and are therefore at particular risk of acquiring UTI. In a cohort and nested case–control study undertaken in six long-term care facilities in Norway, the incidence of UTI was 2 per 1000 resident days [95% confidence interval (CI) 1.8 to 2.2] and they accounted for 40% of infections acquired by residents.14 Risk factors for UTI included being confined to bed [odds ratio (OR) 2.7], an IUC (OR 2.0), skin ulcers (OR 1.8) and urinary incontinence (OR 1.5).14
Although most UTIs in this setting are not associated with an invasive device, the presence of an IUC provides a route for bacteria colonising the perineum to gain access to the bladder and increases the risk of UTI by 3–8% per day.15,16 A prevalence survey of 425 care homes in the UK found 6.9% of the 12,827 resident population had a urinary catheter.17 This study also provided evidence of variation in practice both in relation to discharge from hospital with an IUC and its removal once in the care home, suggesting there is room for a more proactive approach to reducing IUC use.
Urinary tract infection is one of the most common reasons for hospitalisation accounting for one-third of the admissions from care homes.15 In those admitted with BSI, half occur as a result of a urinary source.15 In a study of community-acquired infections in older people admitted to hospital, residents in care home were found to have more comorbidities (p = 0.048) and higher rates of resistant bacteria (70% vs. 36%, p = 0.026) compared to people resident in their own homes.18 Improving understanding of the strategies that could be effective in preventing UTI in in long-term care settings is a priority given the increased susceptibility of this population, the frequency with which UTI occur and the impact on the wider population in terms of acute care resources and increasing antimicrobial resistance.
Prevention strategies
Although the predominant cause of infection among older people is UTI, guidance about strategies for prevention in care homes is limited and mainly focused on urinary catheters.19,20 Guidance does not account for the varying contexts in which care is delivered,21 the challenges presented by residents with complex health needs or the demands of care delivery by unqualified staff with limited supervision.22,23 A systematic review by Lee et al.24 explored evidence for the impact of different components of infection prevention programmes on practice and infection outcomes. Education, monitoring and feedback were identified as essential components in strategies for affecting behavioural changes in healthcare workers at long-term care facilities. However, little is known about the practicality of implementing these approaches in UK care homes.
A recent systematic review of interventions to reduce UTI in nursing home residents identified 19 studies, most of which were small scale, non-randomised before and after studies.25 The majority of these were focused on prevention of infection related to urinary catheters, for example, by replacing indwelling catheters with intermittent or condom catheterisation, ensuring appropriate indication for the catheter and improving management to reduce the risk of UTI. Six studies were focused on improving continence care and bladder training.
Optimising the care of urinary catheters and the use of alternatives to a catheter are key strategies for preventing UTI. Duration of catheterisation is the most important modifiable risk factor for CAUTI16 and so timely review and removal of catheters is imperative. Urinary catheters are commonly inserted in older people while they are in hospital but can remain in place following discharge from hospital when there is no clear plan for review and removal. A recent prevalence survey of patients with an IUC on district nursing caseloads in the UK found a high proportion of newly placed catheters (those placed within 4 weeks in patients without a catheter previously) originated in hospital, with only half having an active management plan likely to result in early removal of the catheter.26 Most patients with a newly placed catheter were men aged 70 years or older, of whom 11% were in residential care or on an assisted living unit.
In residents without a catheter, studies have focused on strategies to reduce the risk of recurrent UTI (RUTI; at least two UTI in 6 months or three in 12 months) using a range of non-antibiotic agents that prevent uropathogens adhering to epithelial tissue in the urinary tract (D-mannose), create an antiseptic environment in the bladder (methenamine hippurate, cranberry) and support natural defences against UTI (probiotics and oestrogen). There is a body of evidence from small-scale trials and systematic reviews, although the efficacy and feasibility of using such approaches in a care home setting are important considerations.27
Recognising urinary tract infection and residents at increased risk in care homes
Mechanisms that support accurate recognition of UTI by care home staff, nurse practitioners and general practitioners (GPs) are critical to driving improvements in UTI prevention as they enable informed assessment of individual residents and monitoring of the effectiveness of prevention strategies (). Overdiagnosis of UTI is a known problem in care homes,28–30 and without accurately distinguishing infection from ASB, it is not possible to measure the impact of prevention strategies. Targeting prevention strategies at those residents at greatest risk of UTI may be a useful approach, but this also requires reliable mechanisms to identify residents who experience recurrent infections.8,25
How recognition of UTI is integral to its prevention.
Accurate recognition of UTI in long-term care is problematic. Many adults over 65 years have ASB and discriminating those who have a UTI when this may present as generalised symptoms such as abdominal or back pain can be difficult.31 In addition, a high proportion of care home residents are living with cognitive impairment or dementia and may not be able to communicate symptoms. Reagent strip tests (dipsticks) are commonly used by care home staff and clinicians as a UTI diagnostic tool despite their unreliability in older people and recommendations in national guidelines to cease their use in this group.20,32,33 Use of urine dipsticks may drive unnecessary antibiotic prescribing for ASB,13 placing individuals at risk of adverse drug effects and more recurrent infections with antibiotic-resistant bacteria.31
Significant resources within primary care would be required to provide full clinical assessments for all suspected UTI cases in care homes and therefore GPs rely on care staff to make clinically accurate observations. Staff working in care homes for older people may have limited ability to distinguish relevant signs and symptoms and limited access to specialist advice. Also, recent emphasis on the importance of early recognition of deterioration and sepsis may bring about an overly cautious approach to escalating concerns to the GP for fear of missing an infection. This creates a tension between reducing unnecessary use of antibiotics in line with antimicrobial stewardship (AMS) and early recognition and treatment of infection, with GPs often providing prescriptions over the phone.
Rates of emergency hospital admissions due to UTI are reported to have increased markedly in England since 2001,34 and one-third of admissions to hospital from care homes are due to UTI.15 UTI prevention is therefore an important driver for reducing admission rates. Older people, particularly those in care homes, are the most vulnerable to UTI; yet, guidance on effective prevention strategies is limited and mostly not directed at this setting. Consequently, there is an urgent need for coherent, evidence-based programmes to support the prevention of UTI that are both relevant and practical to implement in care homes in the UK.
High rates of resistance to antibiotics used to treat UTI have emerged as a major public health problem, with a high proportion of urinary Escherichia coli (E. coli) isolates now resistant to trimethoprim.9 Up to 50% of antibiotics administered in care homes for older people are prescribed for UTI.15,35 However, because UTI is difficult to diagnose accurately in this population, a high proportion of antimicrobial prescriptions is unnecessary,13,36 while if UTI is present, inadequate antimicrobial therapy significantly increases the risk of BSI.7 In the last decade, there has been a rapid, year-on-year, increase in incidence of invasive infections caused by the most common uropathogen, E. coli, with more than 43,000 cases reported in England in 2019.37 The majority of these infections occur as a result of UTI, 68% originate outside acute healthcare settings, 70% occur in adults over 65,11,18 and cases associated with substantial antimicrobial resistance and increases in ambient temperatures.10
In recognition of the important threat to public health presented by these trends in E. coli infections and resistance in uropathogens, a national target was set to reduce the number of Gram-negative BSI by 50% by 2021.38 Since most of these infections occur because of UTIs in elderly people, identifying strategies that prevent UTI and understanding how to implement them effectively are essential to address this target.
The next chapter of the report describes the methods used in the realist synthesis.
