Emergency department attendance stratified by cause and frailty status: A national retrospective cohort study

Aim The aim of this study was to determine whether the causes of emergency department (ED) attendance and clinical outcomes vary by frailty status. Methods Using the Nationwide ED Sample, causes of attendance were stratified by Hospital Frailty Risk Score (HFRS). Logistic regression was used to determine adjusted odds ratios (aORs) and 95% confidence intervals (95% CIs) of ED and overall mortality. Results A total of 155 497 048 ED attendances were included, of which 125 809 960 (80.9%) had a low HFRS (<5), 27 205 257 (17.5%) had an intermediate HFRS (5–15), and 2 481 831 (1.6%) had a high HFRS (>15). The most common cause of ED attendance in the high‐HFRS group was infectious diseases (43.0%), followed by cardiovascular diseases (CVD) (24.0%) and respiratory diseases (10.2%). For the low‐HFRS group, musculoskeletal disease was the most common cause (21.2%), followed by respiratory diseases (20.6%) and gastrointestinal diseases (18.5%). On adjusted analysis, high‐HFRS attendances had increased overall mortality (combined ED and in‐hospital) across most attendance causes, compared with their low‐risk counterparts ( P < 0.001). High‐HFRS attendances with infectious diseases, CVD, and respiratory diseases had an increased risk of overall mortality, compared with their low‐risk counterparts (aOR 23.88, 95% CI 23.42–24.34 for the infectious disease cohort; aOR 2.58, 95% CI 2.55–2.61 for the CVD cohort; and aOR 36.90, 95% CI 36.18–37.62 for the respiratory disease cohort). Conclusions Frailty is present in a significant proportion of ED attendances, with the cause varying by frailty status. Frailty is associated with decreased ED and increased overall mortality across most attendance causes. Geriatr Gerontol Int 2025; ••: ••–•• .