The impact of multidrug resistance in healthcare-associated and nosocomial Gram-negative bacteraemia on mortality and length of stay: cohort study

Abstract

Multidrug-resistant Gram-negative bacteria (MDR-GNB) are an emerging public health threat. Accurate estimates of their clinical impact are vital for justifying interventions directed towards preventing or managing infections caused by these pathogens. A retrospective observational cohort study was conducted between 1 January 2007 and 31 July 2009, involving subjects with healthcare-associated and nosocomial Gram-negative bacteraemia at two large Singaporean hospitals. Outcomes studied were mortality and length of stay post-onset of bacteraemia in survivors (LOS). There were 675 subjects (301 with MDR-GNB) matching study inclusion criteria. On multivariate analysis, multidrug resistance was not associated with 30-day mortality, but it was independently associated with longer LOS in survivors (coefficient, 0.34; 95% CI, 0.21-0.48; p < 0.001). The excess LOS attributable to multidrug resistance after adjustment for confounders was 6.1 days. Other independent risk factors for higher mortality included male gender, higher APACHE II score, higher Charlson comorbidity index, intensive care unit stay and presence of concomitant pneumonia. Concomitant urinary tract infection and admission to a surgical discipline were associated with lower risk of mortality. Appropriate empirical antibiotic therapy was neither associated with 30-day mortality nor LOS, although the study was not powered to assess this covariate adequately. Our study adds to existing evidence that multidrug resistance per se is not associated with higher mortality when effective antibiotics are used for definitive therapy. However, its association with longer hospitalization justifies the use of control efforts.

Increased Costs Associated with Bloodstream Infections Caused by Multidrug-Resistant Gram-Negative Bacteria Are Due Primarily to Patients with Hospital-Acquired Infections

“…The MDR phenotype was not associated with either in-hospital mortality or poor clinical outcome. This is consistent with the literature, as multiple large studies have demonstrated antibiotic resistance to have either a detrimental or neutral effect on clinical outcomes (37)(38)(39)(40). In this study, the assessment of how antibiotic resistance influences clinical outcomes is likely complicated by heterogeneity in bacterial species, antibiotic resistance profiles, and patient clinical factors.…”

Antibiotics in surgical wards: use or misuse? A newly industrialized country’s perspective

“…Prevention and management of infection is imperative as postoperative SSI alone can prolong hospitalization, double readmission rates, and triple the cost of treatment [5]. Inappropriate use of antibiotics, however, can increase resistance towards antibiotics, morbidity, mortality and cost of health-care [6,7,8,9]. This study determined the appropriateness of antibiotic prescription among surgical patients and will act as an important guide in the development and implementation of an effective ASP.…”

Antimicrobial Resistance and Virulence: a Successful or Deleterious Association in the Bacterial World?

“…This is especially true in the hospital environment (intensive care units, burn units, etc. ), in which if a opportunistic pathogen is drug resistant, it can cause disease more readily (12). In environments where selective antibiotic pressure prevails, some opportunistic pathogens are able to colonize new ecological niches because of their plasticity and ability to adapt through the acquisition or development of mechanisms of resistance and persistence.…”