Hospitalisations during the 30-day period preceding admissions with cardiac arrest

Background: Cardiac arrest (CA) is common but deadly. Prior hospitalisation represents a missed opportunity for prevention and identification of high-risk groups before CA. This study aims to determine the extent of and underlying reasons for hospitalisations during the 30-day period preceding an admission with CA. Methods: We conducted a retrospective cohort study using the United States National Readmission Database (NRD) during 2018–2020. We evaluated hospitalisations with a diagnosis of CA and admissions in the 30-day period before hospitalisation with CA. Multiple logistic regressions were used to identify factors associated with prior hospitalisation and mortality on admission with CA. Results: Among 1,637,240 hospital episodes with CA, 255,500 (15.6%) had an admission to hospital in the 30-day period prior to hospitalisation with a diagnosis with CA. The categories for causes of previous admissions were disorders of the circulatory system (27%), infectious and parasite disease (13%), and disorders of the respiratory system (12%). The most common diagnoses were sepsis, hypertensive heart and renal disease, acute myocardial infarction, and respiratory failure. Cancer (OR 2.09 95%CI 2.04–2.15, p < 0.001), chronic kidney disease (OR 1.45 95%CI 1.42–1.48, p < 0.001), and chronic lung disease (OR 1.25 95%CI 1.22–1.27, p < 0.001) were the most significant factors associated with prior admission. Previous hospital admission was associated with increased odds of mortality (OR 1.58 95%CI 1.55–1.62, p < 0.001). Conclusions: Hospitalisations within the 30-day period preceding an admission with CA are common and occur in about 1 out 6 patients. The most common primary diagnoses for prior hospitalisation were sepsis, renal and cardiovascular disease.