Overprescribing antibiotics for asymptomatic bacteriuria in older adults: a case series review of admissions in two UK hospitals

Background: Overdiagnosis and overtreatment of urinary tract infection (UTI) with antibiotics is a concern. In older adults, diagnosis of UTI using near-patient urine tests (reagent strip tests, dipsticks) is advised against because the age-related increase in asymptomatic bacteriuria can cause false-positive results. Instead, UTI diagnosis should be based on a full clinical assessment. Previous research lacks systematic information on urine dipstick use in hospitals. The aim of this study was to examine the use of urine dipstick tests and microbiology among older adult hospital admissions in relation to recommended UTI diagnostic criteria. A further aim was to assess factors associated with the use of dipsticks. Methods: A case series review of patients aged ≥70 years admitted to two NHS Trust hospitals in England. Records from 312 patients admitted in 2015 meeting inclusion criteria were selected at random. Results: Of 298 complete patient records, 54% had at least one urine dipstick test recorded. 13% (21/161) of patients who received a urine dipstick test were diagnosed as having a UTI, only 2 out of these 21 cases had two or more clinical signs and symptoms. 60 patients received a second dipstick test, leading to 13 additional cases of UTI diagnosis. Dipstick tests were more likely to be performed on patients with a history of falls (OR 1.93, 95% CI:1.21, 3.07, p < 0.01), and less likely on those with dementia (OR 0.44, 95% CI: 0.22, 0.87, p < 0.05). The most common reason for testing was routine admissions policy (49.1% of cases), but these cases were predominantly in one hospital. Conclusions: Use of urine dipstick tests was high among older adults admitted to hospitals. Most cases were asymptomatic and therefore received inappropriate antibiotic therapy. This paper highlights the need to implement new Public Health England diagnostic guidelines to hospital admission and emergency departments.