Long-term morbidity and mortality of patients who survived past 30 days from bloodstream infection: A population-based retrospective cohort study

Background: For bloodstream infections (BSI), treatment and research have focused on short term mortality. The objective of this study was to describe the 1-year mortality and morbidity in survivors of bloodstream infection when compared to patients with negative blood cultures. Methods: We conducted a population-based retrospective cohort study using Ontario administrative databases. Patients were included if they had a blood culture taken from January 1, 2014, to December 31, 2021, and survived past 30 days from blood culture collection. They were followed for the subsequent year. Outcomes were compared among patients with BSI and those without BSI, including all-cause mortality, stroke, myocardial infarction (MI), congestive heart failure (CHF) exacerbation, new start dialysis and admission to a long-term care (LTC) facility. Prognostic factors were balanced using overlap weighting of propensity scores, and a survival or competing risk model was used to describe time-to-event. Results: Of 981,341 patients undergoing blood culture testing, 99,080 (10.1%) patients had a BSI and 882,261 (89.9%) patients did not. Outcomes were all more common among those with BSI as compared to those without BSI, including all-cause mortality (16,764 [16.9%] vs. 84,480 [9.6%]), stroke (1016 [1.0%] vs. 4680 [0.5%]), MI (1043 [1.1%] vs. 4547 [0.5%]), CHF exacerbation (2643 [2.7%] vs. 13,200 [1.5%]), new start dialysis (1703 [1.7%] vs. 2749 [0.3%]), and LTC admission (4231 [4.3%] vs. 13,016 [1.5%]). BSI had an adjusted hazard ratio of 1.10 (95% CI 1.08-1.12, P < 0.0001) for mortality, subdistribution hazard ratio (sHR) of 1.27 (95% CI 1.19-1.37, P < 0.0001) for stroke, sHR of 1.18 (95% CI 1.10-1.26, P < 0.0001) for MI, sHR of 1.05 (95% CI 1.01-1.10, P = 0.0176) for CHF exacerbation, sHR of 3.42 (95% CI 3.21-3.64, P < 0.0001) for new start dialysis and sHR of 1.87 (95% CI 1.80-1.94, P < 0.0001) for LTC admission. Conclusion: BSI survivors have substantial long-term mortality and morbidity including stroke, MI, new start dialysis and functional decline leading to LTC admission. (c) 2024 The Author(s). Published by Elsevier Ltd on behalf of The British Infection Association. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).