Death and cardiovascular events after bacteriuria among adult women with chronic kidney disease

Background: The impact of bacteriuria on mortality and cardiovascular risk has not been previously reported for patients with chronic kidney disease (CKD). Objective: To assess the relationship between outpatient episodes of bacteriuria and mortality and cardiovascular risk among women with CKD. Design: Retrospective cohort study using an electronic health database from an integrated healthcare system in central Pennsylvania. Subjects: Adult women with CKD receiving primary care at Geisinger Health System between January 1, 2004 and December 31, 2009 were eligible, and were followed through December 31, 2010 for study outcomes. Main measures: The study exposure was bacteriuria, defined as an outpatient urine culture with bacterial growth of 10(4) cfu/mL. Treatment history (antibiotic prescription within 90 days) was identified. Study outcomes were death and the composite of hospitalization for myocardial infarction, congestive heart failure, or stroke. Multivariate-adjusted Cox models incorporated all bacteriuria episodes and antibiotic prescriptions in time-dependent fashion (in addition to other covariates) to account for the cumulative impact of infections, treatment, and hospitalization during follow-up. Key results: 6807 women were followed for a median (interquartile range) of 5.2 (3.4, 5.9) years. In adjusted models, each untreated bacteriuria episode was associated with an increased risk of death (hazard ratio [HR] 1.56, 95% CI 1.35-1.81) and the composite cardiovascular outcome (HR 1.32, 95% CI 1.05-1.65); treated episodes were not associated with an increased risk of death or cardiovascular events. Conclusion: Among female patients with CKD, untreated bacteriuria occurring in the outpatient setting is associated with an increased risk of death and cardiovascular morbidity.