Hospital length of stay and all-cause 30-day readmissions among high-risk Medicaid beneficiaries

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This study examined the association between index hospitalization characteristics and the risk of all-cause 30-day readmission among high-risk Medicaid beneficiaries using multi-level analyses. A retrospective cohort with a baseline and a follow-up period was used. The study population consisted of Medicaid beneficiaries (21-64 years) with selected chronic conditions, continuous fee-for-service enrollment through the observation period, and at least one inpatient encounter during the follow-up period (N=15,806). The outcome of 30-day readmission was measured using inpatient admissions within 30-days from the discharge date of the first observed hospitalization. Key independent variables included length of stay, reason for admission, and month of index hospitalization (seasonality). Multi-level logistic regression that accounted for beneficiaries nested within counties was used to examine this association, after controlling for patient-level and county-level characteristics. In this study population, 16.7% had all-cause 30-day readmissions. Adults with greater lengths of stay during the index hospitalization were more likely to have 30-day readmissions [AOR=1.03, 95% CI 1.02,1.04]. Adults who were hospitalized for cardiovascular conditions [AOR=1.20, 95% CI 1.08,1.33], diabetes [AOR=1.23, 95% CI 1.10,1.39], cancer [AOR=1.55, 95% CI 1.26,1.90], and mental health conditions [AOR=2.17, 95% CI 1.98,2.38] were more likely to have 30-day readmissions compared to those without these conditions.