TUESDAY, April 23, 2019 (HealthDay News) -- A risk model has been developed and validated for hospital readmission within 30 days after acute myocardial infarction (AMI) in older patients and has demonstrated moderate performance, according to a study published online April 23 in Circulation: Cardiovascular Quality and Outcomes.
John A. Dodson, M.D., M.P.H., from the New York University School of Medicine in New York City, and colleagues conducted a prospective cohort study involving 3,006 patients aged ≥75 years hospitalized with AMI at 94 U.S. hospitals. Participants were assessed for functional impairments in the hospital, including cognition, vision, hearing, and mobility; other variables possibly associated with readmissions were also obtained. Backward selection and Bayesian model averaging were used to derive a risk model (2,004 patients) that was subsequently validated (1,002 patients).
The researchers found that 18.2 percent of patients were readmitted within 30 days. Patients who were readmitted were older, had more comorbidities, and had a higher prevalence of functional impairments, including disability in activities of daily living (17.0 versus 13.0 percent) and impaired functional mobility (72.5 versus 53.6 percent). Eight variables were included in the final risk model; the only functional impairment variable retained was functional mobility, which was the strongest predictor. The model was well calibrated and had moderate discrimination (C statistics: 0.65 and 0.63 in the derivation and validation cohorts, respectively). Performance of the risk model was significantly improved with functional mobility (net reclassification improvement, 20 percent).
"Much of the variability in readmission risk among this older adult population remains unexplained by patient-level characteristics," the authors write.