Acute biological age as a determinant of adverse outcomes requiring hospitalization in Danish emergency department patients

BACKGROUND: Accurate health assessments in the Emergency Department are critical for guiding treatment decisions. However, these assessments are often heavily influenced by chronological age, which does not reflect the variability in physiological health among patients, particularly older adults. Biological age estimation based on biomarkers may better indicate a patient's true health status. However, its use in acute care Emergency Department settings is not established. This study introduces the concepts and corresponding estimates of Acute Biological Age and Acute Difference in Age in the Emergency Department setting and assesses their association with in-hospital care needs following acute conditions.

METHODS: Using data from a prospective study of 6071 Emergency Department patients aged over 18, Acute Biological Age was calculated by converting 30-day mortality risk estimates from a machine-learning model incorporating fifteen biomarkers into biological age expressed in years. Acute Difference in Age was derived from the difference between Acute Biological Age and chronological age. Logistic regressions were used to analyze associations between these estimates and twenty predefined events requiring in-hospital care, with a detailed analysis conducted on nine specific events.

RESULTS: Here, we show that Acute Biological Age and Acute Difference in Age are significantly associated with hospitalization risk. Each additional year of Acute Biological Age increases the odds of requiring intravenous treatments, in-hospital care, extended stays, and admission to intensive care, with odds ratios ranging from 1.03 to 1.05.

CONCLUSIONS: Acute Biological Age and Acute Difference in Age are promising metrics to identify high-risk Emergency Department patients and may improve resource allocation in acute care settings.