With increasing age, the risk of frailty rises due to deterioration of several physiological systems, reducing the body’s reserve capacity. Recognising this vulnerability during care encounters is important both for understanding prognosis and recovery goals, and for planning care to reduce adverse outcomes.

Traditional emergency department (ED) risk stratification methods often fail to detect risks related to frailty, which is why interest in incorporating frailty assessment in EDs has grown. Several instruments have been developed, including the Clinical Frailty Scale (CFS). The CFS has been evaluated across many specialties and is recommended for use in the ED. However, no such research has been conducted in Swedish EDs, and studies under real clinical conditions remain limited.

Therefore, this thesis aims to examine whether the CFS is a useful tool for assessing frailty in older ED patients in Sweden. Specifically, we sought to evaluate its interrater reliability, prognostic accuracy, feasibility and the perspectives of patients.Study I was an observational study assessing IRR by collecting independent CFS assessments from the physician, registered nurse, and assistant nurse responsible for the patient. IRR was assessed in 100 patients, with 300 assessments conducted. IRR was moderate to good, with an ICC of 0.78 (95% CI 0.72–0.84).

Study II examined the prognostic value of the CFS by collecting staff-assessed CFS scores for 1840 older patients. The primary outcome was 30-day mortality, compared between patients with and without frailty. We found that 30-day mortality was significantly higher in patients with frailty compared to those considered robust (7.9% vs 0.9%). Frailty was independently associated with 30-day mortality, with an odds ratio of 6.0 (95% CI 3.0–12.2) after adjusting for confounding factors.

Study III employed a mixed methods design to examine the feasibility of the CFS in an ED setting. We collected data on 4235 ED visits and explored staff experiences through a questionnaire. The overall assessment completion rate was 47%, with more completed in older age groups. The most frequently reported barrier to assessment was high workload. Staff generally perceived the CFS to be relevant, although some questioned its benefits for patients in the ED.

Study IV had a qualitative design and included video-recorded CFS assessments and interviews with patients. A thematic analysis was conducted. Most older patients perceived frailty screening as positive or indifferent, though the experience could further benefit from a better understanding of the assessment’s purpose and consequences. Patients emphasised the importance of relationship-oriented communication, influencing their willingness to share information about their lives.

The CFS demonstrates moderate to good IRR and a strong association with mortality, supporting its usefulness in the ED. However, barriers such as high ED workload and mixed staff perceptions regarding its relevance to ED care impact routine use. Older patients generally respond positively to CFS while it is indicated that it can be further improved with clearer explanations of its purpose and potential consequences.

Background

The growing number of older adults presenting to the Emergency Department (ED) challenges traditional models of acute care, which are often poorly aligned with the complex and heterogeneous needs of this population. Frailty, characterized by decreased physiological reserve and increased vulnerability to stressors, has emerged as a key determinant of adverse outcomes in older patients. However, frailty is not systematically integrated into ED assessment and decision-making, which could be explained by persisting knowledge gaps. Comparison among various frailty assessment instruments in ED settings, has demonstrated good prognostic ability regarding adverse outcomes. Their ease of use in this time- and resource-pressured environment has been evaluated, in which the globally used assessment tool CFS was gauged as usable in the ED. Focus on specific patient groups and research personnel conducting the CFS assessments have limited the generalizability of previous research, resulting in lacking evidence of the instrument’s applicability and usability in actual emergency medicine.

Aim

Since uncertainty remains regarding the instrument’s usefulness in EDs, this thesis aims to answer (1) whether frailty assessment performed by regular ED staff retains prognostic validity in real-world conditions, (2) whether frailty adds relevant predictive value beyond established triage systems, (3) how feasible and acceptable frailty assessment with CFS is within time-pressured ED workflows, and (4) whether frailty-informed routines, assessed with CFS early during the ED visit, can improve operational performance.

Method

This thesis consists of Studies I-IV with observational, both prospective and before-and-after, as well as mixed-method designs. Study I was a prospective observational multicentre study conducted in three EDs in the council of Östergötland, Sweden. Study II was a secondary analysis of Study I. Study III, a mixed-method study, was carried out in the same three EDs as Study I. Study IV was a single-centre observational before-and-after study conducted in the Emergency department of University Hospital of Linköping, Sweden.

Study I investigated the prognostic ability of CFS assessments made by regular ED staff during real-life clinical work. All assessed patients aged 65 years and above were eligible for inclusion. The primary outcome was mortality at 30 days, and secondary outcomes were mortality at 7 and 90 days, admission rate, ED and hospital length of stay (LOS). Outcomes were compared between patients living with frailty (CFS>4) and robust patients (CFS<5). Confounders were adjusted for using logistic regression

Study II investigated the prognostic performance of CFS alone or in connection with the existing warning scores: national early warning score (NEWS), triage early warning score (TEWS) or the rapid emergency triage and treatment system (RETTS) triage tool. The prognostic ability was analysed using logistic regression and the primary and secondary outcomes were the same as Study I and are reported as area under the receiver operating curve (AuROC) scores with 95% confidence intervals (CIs).

Study III was a mixed-method study that examined the feasibility and acceptability of CFS in ED by collecting completion rate of assessed patients and by analysing staff experience gathered via an electronic questionnaire. Open-ended questions in the questionnaire rendered free-text comments which were analysed using qualitative content analysis. Quantitative data were analysed to identify patient-related and organisational factors and reported as descriptive data.

Study IV was a before-and-after observational study of the effects of a frailty-informed routine where patients with CFS >4 were recommended to be prioritised for physician assessment among patients with the same acuity after triage. The primary outcome was ED LOS, and secondary outcomes were time to physician and admission rate. Outcomes were compared between a pre-implementation group (control) and a post- implementation group (intervention).

Results

Mortality was significantly higher in patients with CFS >4 at 30 days (7.9% vs 0.9%) with an adjusted odds ratio of 6.0 (95% CI 3.0-12.2, p < 0.001) in the total of 1840 ED visits that were included in the analysis. There were significant differences in mortality at 7 and 90 days, where mortality was higher for patients living with frailty. The differences remained even after adjusting for confounders. Patients living with frailty also had higher admission rates, longer ED LOS, and longer in-hospital LOS, compared to the robust patients.

A total of 1832 patients were included in Study II, where the association between mortality at 30 days and CFS >4 showed a significant association with an odds ratio of 6.0 (CI 95% 3-12, p < 0.01). Prognostication models demonstrated better prognostic ability in those models with CFS compared to those without and were overall similar in AuROC-values ranging from 0.82-0.83 (95% CI 0.77-0.88, p < 0.05).

Feasibility investigation showed a completion rate of 47% in 4235 ED visits. Assessments were made more frequently if the patients were aged >80 years, arrived by ambulance or during the forenoon. The questionnaire revealed that CFS was thought to be a relevant tool but high workload, unclear purpose for use and critical illness, were barriers for usability in the ED.

A total of 542 ED visits were analysed in the before-and-after study with 248 patients in the pre‐implementation and 294 in the post‐implementation group). Post-implementation showed a reduction in Time to physician from 44 min (IQR 20, 94) to 31 min (IQR 15, 65) (p < 0.001). ED LOS was shortened from 352 (IQR 266, 515) to 319 (IQR 240, 458) minutes (p = 0.014). There was no change in admission rate at 59% versus 60% (p = 0.4).

Conclusion

This thesis confirms the robustness and validity of CFS as a prognostic tool outside of controlled research settings and demonstrates that addition of frailty to conventional triage tools captures risk and vulnerability not reflected in vital signs and chief complaint alone. The CFS provides a more accurate risk prognosis which is valuable for establishing realistic goals-of-care and individualising medical planning. A clear ED routine including early frailty identification and connected actions could improve ED flow and decrease avoidable risks associated with prolonged ED stays, which in turn would benefit both the patients and the ED organisation as a whole.