Cardiology/original research
Effect of Barthel Index on the Risk of Thirty-Day Mortality in Patients With Acute Heart Failure Attending the Emergency Department: A Cohort Study of Nine Thousand Ninety-Eight Patients From the Epidemiology of Acute Heart Failure in Emergency Departments Registry

https://doi.org/10.1016/j.annemergmed.2018.12.009Get rights and content

Study objective

We assess the value of the Barthel Index (BI) in predicting 30-day mortality risk among patients with acute heart failure who are attending the emergency department (ED).

Methods

We selected 9,098 acute heart failure patients from the Acute Heart Failure in Emergency Departments registry who had BI score available both at baseline and the ED visit. Patients’ data were collected from 41 Spanish hospitals during four 1- to 2-month periods between 2009 and 2016. Unadjusted and adjusted logistic regression models were used to assess the association between 30-day mortality and BI score. c Statistics were used to estimate their prognostic value.

Results

The mean baseline BI score was 79.4 (SD 24.6) and the mean ED BI score was 65.3 (SD 29.1). Acute functional decline (≥5-point decrease between baseline BI and ED BI score) was observed in 5,771 patients (53.4%). Within 30 days of the ED visit, 905 patients (9.9%) died. There was a steep inverse gradient in 30-day mortality risk for baseline BI and ED BI score. For instance, compared with BI score=100, a BI score of 50 to 55 doubled the mortality risk both at baseline and the ED visit. At the ED visit, a BI score of 0 to 5 carried a 5-fold increase in risk after adjustment for other risk predictors. In comparison with baseline BI score, ED BI score consistently provided greater discrimination. Neither baseline BI score nor the change in BI score from baseline to the ED visit added further prognostic value to the ED BI score.

Conclusion

Functional status assessed by the BI score at the ED visit is a strong predictor of 30-day mortality in acute heart failure patients, with higher predictive value than baseline BI score and acute functional decline. Routine recording of BI score at the ED visit may help in decisionmaking and health care planning.

Introduction

Acute heart failure is a highly prevalent condition, representing one of the most frequent diagnoses in the emergency department (ED).1 Acute heart failure is a pivotal moment in the course of the disease, characterized by a poor short-term prognosis, in which 30-day mortality approaches 10% and there is a high risk of developing functional impairment.2 The role of the emergency physician is crucial for the initial evaluation, immediate treatment, and disposition decisionmaking.

The assessment of functional status through the Barthel Index (BI) has gained interest in recent years as a relevant prognostic indicator in acute heart failure patients attending the ED.3 Baseline functional status has been described as a short- and midterm prognostic factor in acute heart failure patients.4, 5, 6 Its inclusion in relevant risk scores has been demonstrated to provide additional prognostic value and improve the discriminative ability to classify patients according to their short-term mortality risk.7, 8 To date, the assessment of functional status within the first hours of ED arrival or the deterioration in functional status has received little consideration and has not been studied as a potential risk prognostic factor.9, 10, 11 The Multiple Estimation of Risk Based on the Emergency Department Spanish Score in Patients With Acute Heart Failure risk score has recently emerged as a new tool to readily predict 30-day mortality from the ED visit in acute heart failure patients and includes BI score measured at the ED visit as a novel risk factor among 12 other items related to age, comorbidity, and clinical and analytic data.12 BI score at the ED visit was the risk factor with highest predictive value in the risk model.12 Its value at the ED visit may mirror the baseline functional status and the additional influence of an acute heart failure episode. Therefore, the identification of acute functional decline, evaluated by the change between baseline and ED BI scores, may have an additional prognostic value and become the clinical basis on which to make the disposition decision.9

The aim of this study was to examine the prognostic value of functional status measured by the BI to assess whether BI score at the ED visit better predicts 30-day mortality in comparison with baseline BI score, and whether acute functional decline (difference between baseline and ED visit BI scores) can further improve the prognostic value among patients with acute heart failure attended in the ED.

Section snippets

Study Design and Setting

This was a secondary analysis of the Acute Heart Failure in Emergency Departments registry, which is a prospective observational multicenter cohort study that collects data on patients attending 41 Spanish EDs who receive a final diagnosis of acute heart failure. Hospitals participate in the Acute Heart Failure in Emergency Departments registry voluntarily and are a composition of tertiary and nontertiary hospitals from all areas of the regions, therefore representing a broad spectrum of

Characteristics of Study Subjects

A total of 9,098 patients were included in this analysis, thus excluding 3,745 subjects (29.2%) because of the lack of complete BI measurement (2,023 lacked BI score at the ED visit, 136 lacked baseline BI score, and 1,550 lacked both BI scores) or follow-up (36 patients). Comparisons between Acute Heart Failure in Emergency Departments registry patients included in and excluded from this analysis are reported in Table E1 (available online at http://www.annemergmed.com). Mean age, female sex

Limitations

This study should be interpreted in the context of its limitations. BI score was evaluated by many physicians across participating hospitals. Although it has a good interobserver reproducibility, some degree of variability should be expected. Neither interobserver variability (agreement) nor intraobserver variability (test-retest reliability) was measured in our study; however, it had high interrater reliability (0.95) and test-retest reliability (0.89), as well as high correlations (0.74 to

Discussion

BI score at the ED visit is a strong independent predictor for all-cause 30-day mortality in ED acute heart failure patients, regardless of the BI score categorization approach used. BI score at admission and acute functional decline, which is the difference between baseline and ED BI values, did not add extra predictive value to the use of BI score at the ED visit.

The BI was introduced to evaluate patients with stroke16 but has been used in several chronic conditions to assess disability and

References (27)

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Please see page 590 for the Editor’s Capsule Summary of this article.

Supervising editor: Clare L. Atzema, MD, MSc. Specific detailed information about possible conflict of interest for individual editors is available at https://www.annemergmed.com/editors.

Author contributions: XR, OM, and FJM-S conceived the study and conduced the analysis. OM and FJM-S obtained research funding and supervised the conduct of the registry and data collection. SJP provided statistical advice on study design and analyzed the data. PL, JJ, PH-P, VG, MAR, MJP-D, FRE, RR, JAS, MTV, and HB undertook recruitment of participating centers and patients. XR drafted the article, and all authors contributed substantially to its revision. XR takes responsibility for the paper as a whole.

All authors attest to meeting the four ICMJE.org authorship criteria: (1) Substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data for the work; AND (2) Drafting the work or revising it critically for important intellectual content; AND (3) Final approval of the version to be published; AND (4) Agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Funding and support: By Annals policy, all authors are required to disclose any and all commercial, financial, and other relationships in any way related to the subject of this article as per ICMJE conflict of interest guidelines (see www.icmje.org). The authors have stated that no such relationships exist. This study was partially supported by grants from the Instituto de Salud Carlos III, supported with funds from the Spanish Ministry of Health and Fondo Europeo de Desarrollo Regional (PI15/00773 and PI15/01019) and Fundació La Marató de TV3 (2015/2510). The Emergencies: Processes and Pathologies research group of the Institut d'Investigacions Biomèdiques August Pi i Sunyer receives financial support from the Catalonian Government for Consolidated Groups of Investigation (GRC 2009/1385 and 2014/0313). Dr. Rossello reports receiving support from the SEC-CNIC CARDIOJOVEN fellowship program.

The ICA-SEMES Research Group has received unrestricted support from Orion Pharma and Novartis. The present study was designed, performed, analyzed, and written exclusively by the authors independently of these pharmaceutical companies.

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All members of the ICA-SEMES Research Group are listed in the Appendix.

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