Abstract
BACKGROUND AND AIMS: Blood and urine are the most common culture testing for sepsis patients. This study aimed to compare clinical characteristics and outcomes of sepsis patients by blood and urine culture positivity and to identify factors associated with positive cultures. METHODS: This retrospective study included patients aged ≥16 years with sepsis identified by the Sepsis-3 criteria presenting to the emergency department at four hospitals between 2017 and 2019 in Australia. Patient clinical outcomes were in-hospital mortality, intensive care unit (ICU) admission, hospital length of stay, and representation following discharge. Four culture groups were defined based on the positivity of blood cultures (BC) and urine cultures (UC) ordered within 24 h of triage. RESULTS: Of 4109 patient encounters with sepsis, 2730 (66%) were nonbacteremic, urine culture-negative (BC-UC-); 767 (19%) nonbacteremic, urine culture-positive (BC-UC+); 359 (9%) bacteremic, urine culture-negative (BC+UC-); and 253 (6%) bacteremic, urine culture-positive (BC+UC+). Compared with BC-UC- patients, BC+UC- patients had the highest risk of ICU admission (adjusted odds ratio [AOR] 95% CI: 1.60 [1.18-2.18]) while BC-UC+ patients had lowest risk (adjusted odds ratio [AOR]: 0.56 [0.41-0.76]). BC+UC- patients had the highest risk of 3-day representation (AOR: 1.51 [1.02-2.25]) and second longest hospital stay (adjusted relative risk 1.17 [1.03-1.34]). Antibiotic administration before sample collection for culture was associated with lower odds of positive blood or urine culture results (AOR: 0.38, p < 0.0001). CONCLUSIONS: Enhanced clinical care should be beneficial for nongenitourinary sepsis patients (BC+UC-) who had the highest comparative risk of adverse clinical outcomes. Every effort needs to be made to collect relevant culture samples before antibiotic administration, to follow up on culture results, and tailor treatment accordingly.