Impact of blood culture positivity on clinical outcomes in sepsis: a prospective observational study.

Background: Bacteremia is usually considered a marker for severe infection, yet the correlation between blood culture positivity and mortality in sepsis remains uncertain. This study aimed to evaluate whether blood culture positivity is associated with adverse clinical outcomes in patients with sepsis. Methods: This prospective observational study included adult patients with sepsis admitted to a tertiary care hospital. Patients were classified into culture-positive and culture-negative groups based on blood culture results. Clinical outcomes including 30-day mortality, length of hospital stay, and vasopressor requirement were compared. Multivariable logistic and Cox regression models were used to assess the independent association of bacteremia with mortality, adjusting for age, and comorbidities. Results: Of 633 patients, 41.9% (n=265) were blood culture-positive. Although culture-positive patients had higher SOFA, SAPS II scores, and procalcitonin levels, 30-day mortality was similar between groups (20.8% vs. 26.1%; p=0.12). Length of hospital stay was comparable (median 14 vs. 16 days; p=0.374), as was ICU stay duration (p=0.693). On multivariable analysis, bacteremia was not independently associated with 30-day mortality (adjusted OR 0.62, 95% CI:0.28-1.37, p=0.236). Kaplan-Meier analysis showed a non-significant trend toward higher survival in the culture-positive group (HR 1.30, 95% CI: 0.80-2.10, p=0.293). Conclusions: Although blood culture-positive sepsis was associated with higher disease severity at presentation, it did not result in increased 30-day mortality. These findings suggest that bacteremia alone does not determine sepsis outcomes, and culture-negative sepsis should be managed with equal clinical urgency.