Abstract WP338: The Impact of Social Determinants of Health on 30-Day Readmission After Ischemic Stroke

Abstract

Objective: Readmission after ischemic stroke presents immense social and financial burden on the patient, family and society. The impact of social determinants of health on post-stroke readmission have not been well studied. This study aimed to examine association of patient social determinants with 30-day readmission risk after ischemic stroke. Methods: We examined patients who were hospitalized for acute ischemic stroke (ICD-9 codes 433.1, 434, and 436) in the state of Florida and New York from February 2012 to November 2013, with a 30-day run-in time and 30-day follow up time. Data were obtained from the State Inpatient Database which was then linked with Census data on social determinants at zip code level. Multivariate logistic regression models were generated to study the association of patient factors with 30-day readmission, after adjusting for patient characteristics, in-hospital infection, hemiplegia, and 16 comorbidities. All statistical analyses were conducted using SAS Version 9.4 software (SAS Institute). Results: A total of 127,290 patients were included in the study. The overall 30-day readmission rate was 23%. The 30-day readmission rates differed by race, insurance but not age, sex or household income at zip code level. The 30-day readmission rate was higher amongst black (27%) and Hispanics (25%), and lower in Native American (17%) and White (22%). Comparable to older age groups, patients who suffered a stroke at young age (<50 years old) had 23% readmission rates at 30 days. In the multivariate logistic regression model, age was not a risk factor for readmission [adjusted odds ratio (OR) 1.0, 95% confidence interval (CI) 1.0-1.0]. Compared to white, black race had higher risk of 30-day readmission (OR1.2, 95% CI 1.1-1.2), as well as Hispanic race (OR1.1, 95% CI 1.1-1.2). Compared to Medicare insurance, patient on Medicaid had higher risk of 30-day readmission (OR 1.1, 95% CI 1.1-1.2). Self-pay patients had lower risk of readmission (OR 0.6, 95% CI 0.5-0.7). Conclusion: Race and medical insurance, not age, sex, or household income, has significant influence in30-day readmission risk after ischemic stroke. This will allow further targeted intervention for readmission reduction.