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Emergency-department (ED)-based observation-unit treatment has been shown to reduce inpatient admissions, hospital bed-hours, and costs without adversely affecting outcomes for several conditions. A sequential group design study compared risk-matched, acute decompensated heart failure patients admitted directly to the inpatient setting with those admitted to an ED observation unit for up to 23 hours before ED disposition. Outcomes were 30-day readmissions or repeat ED visits for heart failure or 30-day mortality. Estimates of bed-hours and charges between the groups were compared. Sixty-four patients were enrolled with 36 inpatient admissions and 28 observation unit patients. No patients died within 30 days. Observation unit patients had no significant difference in outcomes, a decrease in time from ED triage to discharge, a saving in mean bed-hours, and less total charges. This pilot trial provides preliminary data that suggest admitted, low-risk heart failure patients may be safely and cost-effectively managed in an ED-based observation unit. These findings need to be further evaluated in a randomized clinical trial.
One third of patients diagnosed with heart failure (HF) receive inpatient care each year, and at least 80% of patients presenting in the emergency department (ED) with HF are hospitalized.1,2 ED patients seen, admitted, and treated in an inpatient bed account for the majority of expenditures for HF care.3 Up to 80% of patients discharged from the hospital with a primary diagnosis of HF come from the ED.2,4,5 Based on American College of Cardiology/American Heart Association or Agency for Health Care Policy Research guidelines, however, it has been suggested that up to 50% of admitted patients are low risk and would have been candidates for outpatient therapy.2,6 This conservative approach to the HF patient is a significant inefficiency in an overburdened health care system.
A novel approach for management of ED HF patients is necessary to decrease the relative burden of this disease. Even with the development of new diagnostic and prognostic tools, the high rate of admissions for HF patients has not changed in decades. Providing the emergency physician with an alternative to hospitalization that still allows for an extended evaluation and treatment would represent a significant advance. An observation-unit (OU) approach may satisfy this goal.7–11
We hypothesized that evaluating and treating low-risk HF patients in an OU would decrease the need for admission, decrease hospital length of stay, and decrease costs as compared with direct admission. We also hypothesized that patients admitted to the OU did not have worse outcomes than those admitted to an inpatient setting. We expected costs to change more than lengths of stay since the cost per day for an observation patient is about one third of that for an admitted patient.
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The results of this pilot study suggest OU management of the low-to-moderate-risk HF patient results in a safe and cost-effective alternative to direct admission to the inpatient setting. There were no deaths experienced during follow-up, and recidivism was not different between the two patient groups. Further, cost savings in the 28 patients admitted to the OU were estimated to amount to more than $100,000 or approximately $3600 per patient.
One of the primary criticisms of OU care is that low-risk patients are placed in the unit when they would otherwise have been discharged. While direct discharge home is another option for the decompensated HF patient, selecting those patients that may be safely discharged home remains difficult; risk-stratification studies have not accurately defined appropriate decision-making criteria.6,12–21 Indeed, a study evaluating HF patients discharged directly from the ED reported a 61% 90-day event rate (death and recidivism).13 Without a prospectively derived HF “risk-score,” emergency physicians must risk-stratify, based on the patient's acute presentation, and social situation, and the physician's previous clinical experience with similar patients. As a result, the majority of patients with HF are admitted.2,23
In our OU, the emergency physician is provided with further opportunity for risk-stratification through testing such as serial cardiac markers, echocardiography, and rest cardiac perfusion imaging. They may also begin aggressive treatment, including the use of IV/p.o. vasodilators and diuretics, and the opportunity they have to provide patient education. These benefits of OU management partially negate the necessity to make a conservative disposition decision based on limited information.
Another area of HF management that needs further investigation is OU treatment end points. Currently, patients are discharged based essentially on two broad criteria: 1) symptomatic improvement; and 2) not fulfilling obvious high-risk features such as positive cardiac markers, electrocardiogram changes, severe electrolyte disturbances, or vital sign abnormalities. However, what have not been delineated are specific treatment goals (e.g., urinary output, jugular venous distention changes, disappearance of an S3, changes in brain natriuretic peptide levels) that could be used to facilitate safe discharge. Other disease processes such as sepsis have been investigated in this manner, and such goal-directed therapy has proven to reduce morbidity and mortality while simultaneously being cost-effective.24
Preliminary studies in HF patients have identified surrogate markers of tissue perfusion (lactate) and ventricular stretch (brain natriuretic peptide) as two potential targets for goal-directed therapy.25,26 However, rigorous, prospective studies, especially of patients in the OU, have not been performed to date.
There are a number of limitations to our study. Though patients were enrolled prospectively, data were collected retrospectively. While this does not affect measurements such as vital signs and laboratory values, it does affect elements pertaining to history taking and patient follow-up. However, patients in our indigent population frequently receive the majority of their care at our institution and history and follow-up for these patients are relatively complete.
The ultimate decision for admission to the OU was left to the treating physician, potentially creating enrollment bias by placing patients in the OU that would normally have been sent home. However, the strong inclination toward conservative disposition (>80% of HF patients are admitted at our institution) of this cohort of patients minimizes the potential for enrollment bias. A formal cost-effectiveness analysis was not performed, and using charges to approximate costs has significant limitations.
Finally, while the two groups were enrolled during different time periods, HF diagnostics and treatment did not change to such a degree during this period as to significantly impact care.
Our results are consistent with other studies. Albert27 reported that the use of the OU to manage HF decreased overall hospital costs. Peacock and Craig,28 using chart review methodology, found that 50% of low-to-moderate-risk HF patients managed in an OU were discharged home with only a 12% readmission rate at 1 month report, that 90-day ED recidivism and hospital readmission decreased by 56% and 64%, respectively, in OU patients.7,29 Methods similar to the OU approach to managing HF have also shown success. For example, Chapman and Torpy30 reported a 30% decrease in hospital admissions for HF after they opened an outpatient HF center operating along guidelines similar to those used in the OU.
While the results from our preliminary analysis are promising, a prospective study randomizing low-to-moderate-risk HF patients to either the inpatient setting or an OU is necessary. This would maximize the likelihood of successful risk matching between groups, and minimizes the chance of enrollment bias. This would also allow for more rigorous data collection and follow-up, including more thorough quantification of economic and quality-of-life costs.