Risk factors for recurrence and death after bacteraemia: a population-based study

Abstract

Although most bacteraemic outcome studies have focused on mortality, a repeated episode(s) is another important outcome of bacteraemia. We sought to characterize patient factors and microbial species associated with recurrence and death from bacteraemia. Population-based surveillance for bacteraemia was conducted in a Canadian health region during 2000-2008. Episodes of bacteraemia were extracted and characterized. Transition intensities of both recurrence and death were estimated by separate multivariate Cox proportional hazards models. We identified 9713 patients with incident episodes of bacteraemia. Within 1 year: 892 (9.2%) had recurrent bacteraemia, 2401 (24.7%) had died without a recurrent episode and 330 (3.4%) had died after a recurrent episode. Independent risk factors for recurrence within 1 year (hazard ratio; 95% confidence interval) were: increasing Charlson comorbidity scores (score 1-2: 2.2; 1.8-2.7 and score 3+: 3.4; 2.8-4.2), origin of infection (nosocomial: 2.1; 1.8-2.6 and healthcare-associated: 2.4; 2.0-2.8), microorganism (polymicrobial: 1.5; 1.2-2.0 and fungal: 2.8; 1.9-4.2) and focus of infection (verified urogenital: 0.4; 0.3-0.6). Independent risk factors for death within 1 year included: a recurrent bacteraemic episode 3.6 (3.1-4.0), increasing age and different foci of infection. This study identifies patient groups at risk of having a recurrent episode and dying from these infections. It adds recurrent bacteraemia as an independent risk factor of death within 1 year and may help to target patients for prevention or changes in management.