Incidence and outcomes of patients admitted to emergency departments with urinary tract infections in Denmark: a retrospective cohort study

Urinary tract infection (UTI) is a common Emergency Department (ED) diagnosis and cause of hospitalization. This study aimed to assess the incidence of UTI-related referrals and admissions in the Region of Southern Denmark and describe patient demographics, clinical and laboratory findings, readmission rates and mortality. This retrospective cohort study included all referrals to five EDs in the Region of Southern Denmark from January 1, 2016, to March 19, 2018. Patients aged ≥18 years, with a UTI discharge diagnosis were included. A total of 3,754 individual UTI patients were identified, corresponding to an incidence of 17.6 per 10,000 person-years and an admission rate of 10.8 per 10,000 person-years. Admitted patients were older (median age: 77 years), had more comorbidities, higher CRP and leukocyte levels (p < .001). E. coli was the most frequent pathogen in both urine (66.6%) and blood cultures (53.6%). Admission was associated with male sex (OR 1.32), age 60-80 years (OR 3.07), ≥81 (OR 3.60), Charlson Comorbidity Index (CCI) ≥3 (OR 1.34), qSOFA = 1 (OR 1.56), and initiation of antibiotic treatment (OR 4.08). Thirty-day mortality was 7.4%, with age ≥81 (OR 3.86), CCI ≥3 (OR 2.73), and qSOFA = 3 (OR 5.49) as significant risk factors. Among patients who were not admitted at the initial contact, 5.1% required hospitalization within 30 days. UTIs are a common cause of hospitalization and represent a substantial healthcare burden in Denmark. Older age, male sex, comorbidities, and severe clinical presentations were key predictors of admission and mortality.