Predictive scoring model of mortality in Gram-negative bloodstream infection

Abstract

Mortality is a well-recognized complication of Gram-negative bloodstream infection (BSI). The aim of this study was to develop a model to predict mortality in patients with Gram-negative BSI by using the Pitt bacteraemia score (PBS) and other clinical and laboratory variables. A cohort of 683 unique adult patients who were followed for at least 28 days after admission to Mayo Clinic Hospitals with Gram-negative BSI from 1 January 2001 to 31 October 2006 and who received clinically predefined appropriate empirical antimicrobial therapy was retrospectively identified. Multivariable logistic regression was used to identify independent risk factors for 28-day all-cause mortality. Regression coefficients from a multivariable model were used to develop a risk score to predict mortality following Gram-negative BSI. Malignancy (OR 3.48, 95% CI 1.94-6.22), liver cirrhosis (OR 5.42, 95% CI 2.52-11.65), source of BSI other than urinary tract or central venous catheter infection (OR 5.54, 95% CI 2.42-12.69), and PBS (OR 1.98, 95% CI 0.92-4.25 for PBS of 2-3 and OR 6.42, 95% CI 3.11-13.24 for PBS ≥4) were identified as independent risk factors for 28-day mortality in patients with Gram-negative BSI. A risk-score model was created by adding points for each independent risk factor, and had a c-statistic of 0.84. Patients with risk scores of 0, 4, 8, 12 and 16 had estimated 28-day mortality rates of approximately 0%, 3%, 14%, 45%, and 81%, respectively. The Gram-negative BSI risk score described herein estimated mortality risk with high discrimination in patients with Gram-negative BSI who received clinically adequate empirical antimicrobial therapy.

Stratification of the Impact of Inappropriate Empirical Antimicrobial Therapy for Gram-Negative Bloodstream Infections by Predicted Prognosis

“…Whereas the initial derivation and validation cohorts in Minnesota included a predominantly white population (7,8), the current study in South Carolina included a more diverse ethnic population.…”

“…The BSIMRS is based on acute severity of illness, as summarized by the Pitt bacteremia score (9), source of infection, and major underlying medical conditions that are independently associated with mortality (Table 1). There is a substantial increase in predicted 28-day mortality following Gram-negative BSI as the BSIMRS increases from 0 to 16 (7,8).…”

“…A risk score recently has been derived and validated to predict the outcome of patients at the time of diagnosis of Gram-negative BSI. The BSI mortality risk score (BSIMRS) has a high discriminative ability to predict the prognosis of patients with Gram-negative BSI in both referral and population-based settings (7,8). The BSIMRS is based on acute severity of illness, as summarized by the Pitt bacteremia score (9), source of infection, and major underlying medical conditions that are independently associated with mortality (Table 1).…”

Prediction of Fluoroquinolone Resistance in Gram-Negative Bacteria Causing Bloodstream Infections

“…Fluoroquinolone use within 180 days prior to BSI was analyzed as a categorical variable: none, within 90 days, and within 91 to 180 days from BSI. Variables that were associated with FQ-R in the univariate logistic regression model with a P value of Ͻ0.10 were included in multivariate logistic regression models to identify independent risk factors for FQ-R. Variables were retained in the final model if they were independently associated with FQ-R with a P value of Ͻ0.05 in multivariate logistic regression models using the likelihood ratio test method and individually retained in Ն70% of 200 bootstrap samples (17). Each bootstrap sample was derived by applying the same model selection criteria.…”

Bloodstream infections in patients with liver cirrhosis

“…14,15 In different studies including both cirrhotic and non-cirrhotic patients with bacteriemia or candidemia, LC was found to be an independent predictor of mortality. [16][17][18] The present review focuses on epidemiology, risk factors for mortality, complication of BSI and therapeutic principles in patients with LC. All these aspects are closely related to the unique pathophysiology of the infectious risk in this patient population.…”