Antibiotic management of urinary tract infection in the elderly in primary care and its association with bloodstream infections and all-cause mortality: a population-based cohort study

Abstract

OBJECTIVE To evaluate the association between severe adverse outcomes and the antibiotic treatment for urinary tract infection (UTI) diagnosed in elderly adults in primary care. DESIGN A retrospective population-based cohort study. SETTING Clinical Practice Research Datalink (2007-2015) primary care records linked to Hospital Episode Statistics and death records in England. PARTICIPANTS Patients aged≥65 years presenting to a General Practitioner (GP) with at least one diagnosis of suspected or confirmed lower UTI from November 2007 to May 2015. MAIN OUTCOME MEASURES Bloodstream infection (BSI), hospital admission and all-cause mortality within 60 days following the index UTI diagnosis. RESULTS Among 312,896 UTI episodes (157,264 unique patients), 7% did not have a record of having been prescribed antibiotics and 6% showed a delay in antibiotic prescribing. 1,539 episodes of BSI were recorded within 60 days following the initial UTI. The rate of BSI was significantly higher among those patients who were not prescribed an antibiotic (2. 9%) and those patients recorded as returning to the GP within 7 days of the initial consultation for an antibiotic prescription (2.2%), compared with those given a prescription for an antibiotic at the initial consultation (0.2%) (p=0.001). After adjustment for covariates, patients were significantly more likely to experience a BSI in the ‘deferred antibiotics’ and ‘no antibiotics’ groups compared with the ‘immediate antibiotics’ group (aOR=7.12 [95% CI 6.22 to 8.14] and aOR=8.08 [95% CI 7.12 to 9.16]). The Number Needed to Harm (NNH) for occurrence of BSI was lower (greater risk) for the ‘no antibiotics’ group (NNH=37) than for the ‘deferred antibiotics’ group (NNH=51), relative to the ‘immediate antibiotics’ group. The rate of hospital admissions was approximately double among cases with ‘no antibiotics’ (27%) and ‘deferred antibiotics’ (27%) compared with those prescribed ‘immediate antibiotics' (15%) (p=0.001). The risk of all-cause mortality was significantly higher with ‘deferred antibiotics’ and ‘no antibiotics’ than with ‘immediate antibiotics’ at any time during the 60 days follow-up (aHR=1.16 [95% CI, 1.06 to 1.27] and aHR=2.18 [95% CI, 2.04 to 2.33], respectively). Male patients over 85 years of age were particularly at risk for both BSI and 60 day all-cause mortality. CONCLUSIONS There was a significant increase in BSI and all-cause mortality associated with ‘no antibiotics’ and ‘deferred antibiotics’ compared with ‘immediate antibiotics’ in elderly adults diagnosed with UTI in primary care. In the context of an increase of E. coli BSIs in England, early initiation of recommended first-line antibiotics for UTI in the older adult population is advocated.