Positive Culture and Prognosis in Patients With Sepsis: A Prospective Cohort Study

Purpose: To analyze the prognostic role of positive cultures in patients with sepsis. Methods: A prospective cohort study in a tertiary referral hospital in Medellin, Colombia. Adults older than 18 years of age with a bacterial infection diagnosis according to Centers for Disease Control criteria and sepsis (evidence of organ dysfunction) were included. A logistic regression model was used to determine the association between positive cultures and hospital mortality, and a Cox regression with a competing risk modeling approach was used to determine the association between positive cultures and hospital stay as well as secondary infections. Results: Overall, 408 patients had positive cultures, of which 257 were blood culture, and 153 had negative cultures. Patients with positive cultures had a lower risk of mortality (odds ratio [OR], 0.43; 95% confidence interval [CI], 0.27-0.68), but this association was not maintained after adjusting for confounding factors (OR, 0.56; 95% CI, 0.31-1.01). No association was found with the hospital stay (adjusted subhazard ratio [SHR], 1.06; 95% CI, 0.83-1.35). There was no association between positive cultures and the presence of secondary infections (adjusted SHR, 0.99; 95% CI, 0.58-1.71). Conclusion: Positive cultures are not associated with prognosis in patients with sepsis.