Research has questioned the safety of delaying or withholding antibiotics for suspected urinary tract infection (UTI) in older patients. We evaluated the association between antibiotic treatment for lower UTI and risk of bloodstream infection (BSI) in adults aged ≥65 years in primary care.
We analyzed primary care records from patients aged ≥65 years in England with community-onset UTI using the Clinical Practice Research Datalink (2007–2015) linked to Hospital Episode Statistics and census data. The primary outcome was BSI within 60 days, comparing patients treated immediately with antibiotics and those not treated immediately. Crude and adjusted associations between exposure and outcome were estimated using generalized estimating equations.
A total of 147,334 patients were included representing 280,462 episodes of lower UTI. BSI occurred in 0.4% (1,025/244,963) of UTI episodes with immediate antibiotics versus 0.6% (228/35,499) of episodes without immediate antibiotics. After adjusting for patient demographics, year of consultation, comorbidities, smoking status, recent hospitalizations, recent accident and emergency (A&E) attendances, recent antibiotic prescribing, and home visits, the odds of BSI were equivalent in patients who were not treated with antibiotics immediately and those who were treated on the date of their UTI consultation (adjusted odds ratio [aOR] 1.13, 95% CI 0.97–1.32, p-value = 0.105). Delaying or withholding antibiotics was associated with increased odds of death in the subsequent 60 days (aOR 1.17, 95% CI 1.09–1.26, p-value < 0.001), but there was limited evidence that increased deaths were attributable to urinary-source BSI.
Limitations include overlap between the categories of immediate and delayed antibiotic prescribing, residual confounding underlying differences between patients who were/were not treated with antibiotics, and lack of microbiological diagnosis for BSI.
In this study, we observed that delaying or withholding antibiotics in older adults with suspected UTI did not increase patients’ risk of BSI, in contrast with a previous study that analyzed the same dataset, but mortality was increased. Our findings highlight uncertainty around the risks of delaying or withholding antibiotic treatment, which is exacerbated by systematic differences between patients who were and were not treated immediately with antibiotics. Overall, our findings emphasize the need for improved diagnostic/risk prediction strategies to guide antibiotic prescribing for suspected UTI in older adults.
In a study of electronic health record data, Laura Shallcross, Patrick Rockenschaub and colleagues investigate the associations between initiation of antibiotic treatment for UTI and blood stream infection and mortality among older adults in England.
Urinary tract infections (UTI) are common in older adults and, alongside respiratory infections, account for the majority of antibiotics prescribed in primary care
Antibiotics are often prescribed inappropriately for UTI in the elderly, but the need to reduce prescribing must be balanced against the risk of increasing rare but severe outcomes, such as bloodstream infection, if antibiotic treatment is delayed
A recent study in patients aged >65 years found that those who did not receive immediate antibiotic treatment for UTI were more likely to develop bloodstream infection
We reanalyzed the relationship between the timing of antibiotic prescribing for UTI and subsequent risk of bloodstream infection (BSI) using the same dataset
We did not find evidence to suggest that not immediately prescribing antibiotics for UTI increased a patient’s risk of bloodstream infection, but we did find some evidence of increased mortality.
Women were less likely to develop BSI compared with men (adjusted odds ratio [aOR] 0.49, 95% confidence interval [CI] 0.43–0.55, p-value < 0.001). Increasing age (aOR 1.22, 95% CI 1.18–1.27 per 5 years, p-value < 0.001) and social deprivation (Q5 versus Q1: aOR 1.45; 95% CI 1.19–1.76, p-value < 0.001) were also independently associated with BSI.
Systematic differences between patients who were/were not treated immediately with antibiotics (residual confounding) remains a potential explanation for our findings in relation to mortality.
This population-based study highlights uncertainty around whether delaying antibiotics in older adults with suspected UTI increases their risk of adverse outcomes.
The reasons for the systematic differences identified between patients who were and were not treated immediately with antibiotics warrants further study.
Adverse consequences of antibiotic treatment in this population and the public health need to tackle antibiotic resistance highlight the need for novel diagnostic and/or risk prediction strategies to guide antibiotic prescribing decisions for suspected UTI.