Association between medication-related adverse events and non-elective readmission in acute ischemic stroke

There is limited data on the effects of medication-related adverse events occurring during inpatient stays for stroke. The objectives of our study were to characterize reasons for acute readmission after acute ischemic stroke (AIS) and determine if medication-related adverse events occuring during AIS hospitalization were associated with 30-day readmission. Secondary objectives examined whether demographic, clinical, and hospital characterisitcs were associated with post-AIS readmission.

We used the Nationwide Readmission Database to identify index AIS hospitalizations in the United States between January and November 2014. Inpatient records were screened for diagnostic and external causes of injury codes indicative of medication-related adverse events, including adverse effects of prescribed drugs, unintentional overdosing, and medication errors. Nationally representative estimates of AIS hospitalizations, medication-related adverse events, and acute non-elective readmissions were computed using survey weighting methods. Adjusted odds of readmission for medication-related adverse events and select characteristics were estimated using unconditional logistic regression.

We identified 439,682 individuals who were hospitalized with AIS, 4.7% of whom experienced a medication-related adverse event. Overall, 10.7% of hospitalized individuals with AIS were readmitted within 30 days of discharge. Reasons for readmission were consistent with those observed among older adults. Inpatients who experienced medication-related adverse events had significantly greater odds of being readmitted within 30 days (adjusted odds ratio (AOR): 1.22; 95% CI: 1.14-1.30). Medication-related adverse events were associated with readmission for non-AIS conditions (AOR, 1.26; 95% CI: 1.17-1.35), but not with readmission for AIS (AOR, 0.91; 95% CI: 0.75-1.10). Several factors, including but not limited to being younger than 40 years (AOR, 1.12; 95% CI: 1.00-1.26), Medicare insurance coverage (AOR, 1.33; 95% CI: 1.26-1.40), length of stay greater than 1 week (AOR, 1.38; 95% CI: 1.33-1.42), having 7 or more comorbidites (AOR, 2.20; 95% CI: 2.08-2.34), and receiving care at a for-profit hospital (AOR, 1.20; 95% CI: 1.12-1.29), were identified as being associated with all-cause 30-day readmission.

In this nationally representative sample of AIS hospitalizations, medication-related adverse events were positively associated with 30-day readmission for non-AIS causes. Future studies are necessary to determine whether medication-related adverse events and readmissions in AIS are avoidable.