24-hour limit: development of a calculator to estimate mortality attributable to delayed admission from the emergency department in patients older than 75 years

Objectives.

Prolonged waiting time for hospital admission from emergency departments (boarding) has been consistently associated with increased in-hospital mortality, particularly among older patients. However, translating this increase in relative risk into a specific population-level clinical impact remains limited, hindering its incorporation into organizational decision-making.

Objective.

To develop a clinical impact calculator aimed at estimating the number of potentially preventable in-hospital deaths associated with reducing emergency department stays exceeding 24 hours in patients aged 75 years or older.

Methods.

We developed a conceptual model based on hospital structural and health care delivery data and risk estimates derived from the scientific literature. Exposure was defined as waiting > 24 hours for hospital admission. Impact was estimated by calculating the attributable fraction among exposed individuals, applying different exposurereduction scenarios and performing sensitivity analyses.

Results.

The calculator enables transformation of relative risks derived from observational studies and meta-analyses into absolute estimates of potentially preventable deaths, expressed as monthly or annual periods. The estimated number of potentially preventable deaths was approximately 124 annual cases in the baseline scenario (RR, 1.3), reaching approximately 239 cases in higher-vulnerability scenarios (RR, 1.8). Although based on aggregated realworld data, these figures should be interpreted as population-level estimates derived from a model and do not constitute causal clinical validation. The model allows estimation of the impact of reducing the proportion of patients remaining in emergency departments for more than 24 hours on in-hospital mortality.

Conclusions.

Reducing prolonged waiting times for hospital admission from emergency departments could prevent a substantial number of in-hospital deaths among older patients. The developed tool facilitates consideration of the 24-hour limit as a patient safety standard and supports implementation of organizational strategies aimed at minimizing
boarding.