Associations Between Frailty, Illness Severity, and Long-Term Mortality Among Older Adults Admitted to Municipal Acute Care

Objectives: Important risk factors for mortality include frailty and illness severity. The National Early Warning Score 2 (NEWS2) is widely used to assess acute illness severity and mortality risk, but age and frailty's impact on the association between NEWS2 and mortality is less understood, particularly in nonhospital settings. This study aimed to examine the associations between frailty, NEWS2, and 1-year postdischarge mortality in older adults admitted to the Oslo Municipal In-Patient Acute Care (MipAC) unit. Design: Prospective observational study. Setting and Participants: Patients admitted to the MipAC unit with 1-year follow-up for all-cause mortality. Methods: Frailty was assessed using the Clinical Frailty Scale (CFS). The maximum registered NEWS2 during admission was obtained from patient records. Associations with 1-year mortality were analyzed using a Cox model and Kaplan-Meier survival analysis. Results: Among 382 patients (mean age, 84.3 years; 72% female), 58 died during the 1-year follow-up period. Both CFS and NEWS2 were independently associated with 1-year mortality in an age-adjusted Cox proportional hazards model. The adjusted hazard ratios were 1.33 (95% CI, 1.07-1.66) per unit increase in CFS and 1.26 (95% CI, 1.14-1.39) per unit increase in NEWS2. A supplementary analysis of the vital signs contributing to NEWS2 revealed that elevated respiratory rate and hypotension were independently associated with increased 1-year mortality, with adjusted hazards ratios being 2.71 (95% CI, 1.35-5.46) and 3.05 (95% CI, 1.54-6.01), respectively. When combining CFS and NEWS2, moderately to severely frail patients (CFS >= 6) with low NEWS2 (0-4) showed a tendency toward increased mortality, whereas among those with high NEWS2 (>= 5), frailty did not appear to further influence mortality risk. Conclusions and Implications: CFS, NEWS2, and the vital signs elevated respiratory rate and hypotension are associated with 1-year mortality in patients admitted to a MipAC unit. (c) 2025 The Author(s). Published by Elsevier Inc. on behalf of Post-Acute and Long-Term Care Medical Association. This is an open access article under the CC BY license (http://creativecommons.org/licenses/ by/4.0/).