#87 Hospital readmissions among individuals with severe kidney disease hospitalized for fluid overload
Authors: Cai Jiashen , Huang Zhihua , Lim Lydia , Loo Felicia , Ng L I Choo , Kadir Hanis Abdul , Kwek Jia Liang , Choo Jason , Tan Chieh Suai , Lim Cynthia 
Published: May 2024

Abstract

Background and Aims
Fluid overload is a common presentation and a leading cause for hospitalizations in severe kidney disease, but interventions can help reduce readmissions. To identify at-risk individuals, we evaluated the incidence and risk factors associated with fluid overload and all-cause hospital readmission among individuals with severe kidney disease.

Method
Single-center retrospective cohort study of patients hospitalized in Singapore General Hospital for fluid overload between 2015 and 2017. Fluid overload was identified from discharge codes for fluid overload, heart failure, pulmonary edema, and generalized edema. Patients were included if their estimated glomerular filtration rate (eGFR) was between 11 and 30 ml/min/1.73 m2, but excluded if they had urgent indications for dialysis or were lost to follow-up (Fig. 1). Baseline data on demographics, comorbidities, biochemistry and medication use during admission were retrieved from electronic medical records up till 30th December 2018. The outcomes were fluid overload-related and all-cause readmissions within 30 days of discharge of the index hospitalization. Multivariable logistic regression analysis (stepwise method) was performed with inclusion of covariates with P ≤ .10 on univariate analysis.

Results
Among 783 patients, the median age was 75 (IQR 67, 83) years and the admission eGFR was 20.9 (IQR 16.1, 25.4) ml/min/1.73 m2 at index hospitalization. 30-day readmission for fluid overload and all-causes occurred in 10.6% and 26.8% of the cohort, respectively (Table 1).
Individuals with fluid overload readmissions were more likely to have atherosclerotic cardiovascular disease (ASCVD), atrial fibrillation (AF), prior hospitalization for fluid overload within 6 months, lower serum sodium and bicarbonate, but higher serum potassium at admission (Table 1). They were less likely to have hypertension, prior nephrology consult within 3 months and renin-angiotensin system (RAS) blocker prescription at discharge. In multivariable analysis, 30-day readmission for fluid overload was independently associated with ASCVD (adjusted odds ratio (aOR) 1.81, 95% CI 1.08-3.03, P = .02), AF (aOR 1.93, 95% CI 1.13-3.29, p = 0.02), higher serum potassium (aOR 1.61, 95% CI 1.14-2.26, P = .007), high-dose intravenous furosemide (aOR 1.66, 95% CI 1.02-2.67, P = .04), and inversely associated with prior nephrology consult (aOR, 0.51, 95% CI 0.29-0.89, P = .02) and RAS blocker prescription at discharge (aOR 0.61, 95% CI 0.38-0.99, P = .04).
Individuals with all-cause readmissions were more likely to have AF, more frequent emergency department visits within 6 months, lower eGFR and serum sodium, but higher serum potassium on admission, longer length of stay and higher LACE index (Table 1). They were less likely to have hypertension, RAS blocker and statin prescription at discharge. 30-day readmission for all-causes was independently associated with higher number of emergency department visits (aOR 1.21, 95% CI 1.04-1.40, P = .02), higher LACE index (aOR 1.08, 95% CI 0.001-1.17, P = .048), and inversely associated with mineralocorticoid receptor blocker (aOR 0.55, 95% CI 0.31-0.97, P = .04) and statin prescription at discharge (aOR 0.51, 95% CI 0.33-0.78, P = .002) in multivariable analysis.

Conclusion
Risk stratification of patients with severe kidney disease who are at-risk of fluid overload and all-cause readmissions may allow for targeted interventions to reduce hospital readmissions.