Antibiotic prescribing for lower UTI in elderly patients in primary care and risk of bloodstream infection: a cohort study using electronic health records

Background 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. Methods We analysed 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. Findings 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. 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: 0.97-1.31). However, 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). Interpretation Evidence on the safety of delaying or withholding antibiotics in older adults with suspected UTI is conflicting. Given the prevalence of asymptomatic bacteriuria in this population, their risk of antibiotic-related side effects, and the public health need to tackle antibiotic resistance, we recommend a trial to address this uncertainty.