Hospital Readmissions for All-Causes and Fluid Overload in Severely Reduced Kidney Function Not Requiring Dialysis-A Retrospective Cohort Study

Abstract

Aim: Chronic kidney disease is associated with frequent readmissions for ambulatory-sensitive conditions such as fluid overload. There is a paucity of literature to identify individuals at high risk of fluid overload or all-cause readmissions.

Methods: We performed a single-centre retrospective cohort study involving 783 patients with an estimated glomerular filtration rate of 11-30 mL/min/1.73 m² hospitalised for fluid overload between 2015 and 2017. Multivariable logistic regression analysis was performed to evaluate associations between the 30-day fluid overload-related and all-cause readmissions and various sociodemographic factors, comorbidities and healthcare utilisation.

Results: The 30-day readmission rate for fluid overload and all causes were 10.6% and 26.8%, respectively. Fluid overload readmissions were associated with atherosclerotic cardiovascular disease (ASCVD; adjusted odds ratio [aOR] 1.81, 95% CI 1.08-3.03), atrial fibrillation (AF; aOR 1.93, 95% CI 1.13-3.30), higher serum potassium (aOR 1.61, 95% CI 1.14-2.26) and use of high-dose intravenous furosemide during the index hospitalisation (aOR 1.66, 95% CI 1.02-2.67). In contrast, prior nephrology consult (aOR, 0.51, 95% CI 0.29-0.89) and renin-angiotensin system (RAS) blocker prescription at discharge (aOR 0.61, 95% CI 0.38-0.99) were associated with reduced risk of readmission for fluid overload. More frequent emergency department visits (aOR 1.21, 95% CI 1.04-1.40) and higher LACE score (aOR 1.09, 95% CI 1.01-1.18) were independently associated with 30-day readmission for all causes. Hypertension (aOR 0.62, 95% CI 0.42, 0.93), antidepressant use (aOR 0.40, 95% CI 0.16-0.99) and statin prescription at discharge (aOR 0.53, 95% CI 0.35-0.81) were associated with reduced risk for all-cause readmissions.

Conclusion: Factors related to comorbidity burden (ASCVD, AF, more frequent emergency department visits and higher LACE score) and disease severity (higher serum potassium and need for high-dose intravenous furosemide) can identify individuals at increased risk of readmission. Further research is required to evaluate the impact of modifiable factors (nephrology consult, RAS blocker prescription at discharge and statin prescription at discharge) to reduce fluid overload-related and all-cause readmissions.

Keywords: fluid overload; hospitalisation; kidney disease; readmission.