Home-Time, Mortality, and Readmissions Among Patients Hospitalized With Heart Failure: A Baseline Prior to IMPLEMENT-HF.
Oct 9, 2024DOI: 10.1161/circheartfailure.124.011795Journal ArticleAHA
Written by: Amber B TangNicole SolomonKaren ChiswellStephen J GreeneClyde W YancyMariell JessupMichelle KittlesonJaved ButlerNancy K SweitzerLee R GoldbergJo-Ann LindenfeldEldrin F LewisPamela N PetersonSara PaulLynn Mallas SerdynskiChristine RutanMichelle CongdonSruthi CherkurGregg C Fonarow
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MK
Dr. Michelle Kittleson
Advanced Heart Failure · Cedars-Sinai
NS
Dr. Nancy Sweitzer
Advanced Heart Failure · WUSTL
Background
Heart failure is associated with significant morbidity and mortality and is the leading cause of hospitalizations with nearly one in four patients readmitted within 30 days of discharge.1–3 While mortality and readmission rates have been widely studied in the context of heart failure, these clinical endpoints may not fully account for the overall patient experience. The concept of home-time has been suggested as a patient-centered outcome that can be easily calculated from administrative claims data. Home-time is associated with patient-reported outcomes and quality of life4–6 and reflects the amount of time a patient spends both alive and outside of the hospital, skilled nursing facility (SNF), or acute rehabilitation center. Patients have previously identified time spent at home and outside of the hospital or other healthcare facilities as a priority, second only to maintaining independent self-care.7 Home-time has also been reported as a useful measure of functional status after ischemic stroke and in the post-operative period.8–10While prior studies have suggested that patients hospitalized with heart failure experience substantial reductions in home-time, the use of home-time as an outcome of interest in heart failure populations is still not well-established.11,12 Furthermore, the impact of quality improvement interventions on home-time has not been previously evaluated.13 Therefore, we sought to further characterize home-time among patients hospitalized for heart failure as well as establish a baseline for home-time and other clinical outcomes prior to initiation of IMPLEMENT-HF, an American Heart Association multi-center quality improvement initiative aimed at optimization of inpatient heart failure management.
Methods
The data that support the findings of this study are available from the corresponding author upon reasonable request. This retrospective cohort study evaluated patients hospitalized for heart failure at participating Get With The Guidelines-Heart Failure (GWTG-HF) registry sites. The GWTG-HF registry is an ongoing, nationwide quality improvement registry sponsored by the American Heart Association. In brief, participating sites prospectively collect data for patients hospitalized with decompensated heart failure including medical history, hospital characteristics, vital signs and laboratory values, echocardiographic data, medications, and in-hospital outcomes using standardized case report forms.14 IQVIA (Parsippany, New Jersey) serves as the data collection and coordinating center. Each participating hospital received either human research approval to enroll cases without individual patient consent under the common rule, or a waiver of authorization and exemption from subsequent review by their institutional review board. The Duke Clinical Research Institute serves as the data analysis center and has an agreement to analyze the aggregate limited data for research purposes. The Institutional Review Board at Duke University Health approved this study. To assess post-discharge outcomes and health care costs, participants 65 years of age and older with fee-for service Medicare were included. Medicare coverage was linked to Medicare data using a previously validated methodology.15
The current study included patients enrolled in fee-for-service Medicare admitted to participating GWTG-HF hospitals with a primary diagnosis of heart failure between July 1, 2019 and June 30, 2021. Exclusion criteria included patients with missing gender, left ventricular ejection fraction (EF), or disposition location as well as patients who were transferred to an acute care facility, discharged against medical advice, or discharged to hospice. Sites with more than 25% missing medical history data were also excluded. Among patients with multiple hospitalizations, the first incident within the study period was used as the index hospitalization.
Baseline characteristic information was collected, which included demographic information, comorbidities, vital signs and labs at admission and discharge, and discharge disposition. Guideline directed medical therapy prescribed at discharge was also collected and included data on beta blockers, angiotensin converting enzyme inhibitors (ACEI), angiotensin receptor blockers (ARB), angiotensin receptor-neprilysin inhibitors (ARNI), and mineralocorticoid receptor antagonists (MRA). Subgroup analyses were performed by EF, age, sex, race, ethnicity, and socioeconomic deprivation index score. EF was categorized as reduced (HFrEF, ≤40%), mildly reduced (HFmrEF, 41–49%), or preserved (HFpEF, ≥50%). The socioeconomic deprivation index score was categorized by tertiles based on Neighborhood Deprivation Index score estimates derived from the 2017–2021 American Community Survey as previously described.16
IMPLEMENT-HF is an American Heart Association national collaboration across seven regions in the United States that targets improvements in heart failure management through continuous performance evaluations and identification of care gaps with guided implementation of tailored quality improvement plans. Data from hospitals enrolled in the IMPLEMENT-HF study were analyzed and compared to the larger cohort of patients from the GWTG-HF population.
The primary outcomes of interest were 30-day and 1-year home-time, which was defined as the number of days alive and outside of a hospital, SNF, or inpatient rehabilitation facility after discharge from an index hospitalization for heart failure. The number of inpatient days at a healthcare facility was determined using inpatient Medicare and SNF administrative claims. Secondary outcomes included heart failure readmissions, all-cause readmissions, mortality, as well as composite readmission and mortality endpoints. Cardiovascular death was defined as mortality within 28 days of hospitalization for a primary cardiovascular cause as previously described.17
Descriptive statistics were calculated for the overall population as well as subgroups based on demographic and socioeconomic characteristics. Data were reported as percentages or, when applicable, as mean (standard deviation) and median [first quartile, third quartile]. Missing data among subgroup characteristics were excluded from analysis and are summarized in Table S1. P-values were calculated using chi-squared rank-based group means score statistics for categorical variables and chi-squared rank correlation statistics for continuous variables. Due to large sample sizes, which may artificially deflate p-values, absolute standardized differences (ASDs) were also calculated with a threshold of >10% considered to be significant.18 Correlation between home-time and time to death, time free from death or readmission, and time free from death or heart failure readmission was calculated using Kendall’s tau-b correlation. Histograms were created to show the distribution of home-time as well as the cumulative number of days lost to SNF, acute rehabilitation stays, hospitalization, and death over time. Kaplan-Meier incidence curves were created for one-year time-to-event outcomes including (1) mortality, (2) readmission, and (3) a composite outcome of mortality and readmission. All analyses were performed using SAS software, version 9.4.
Results
In total, 66,019 patients with a median age of 80 [73, 87] years across 437 sites were included. Patients were predominantly white and non-Hispanic, as shown in Table 1. While patients with preserved EF were predominantly female (61.9%), those with reduced EF were mostly male (62.1%), ASD = 49.3%. Over half of patients had atrial fibrillation or flutter and 55% of patients had ischemic cardiomyopathy. Comorbid hypertension and diabetes were also common with a prevalence of 87.7% and 44.5% respectively. The median EF was 53% [35%, 60%] with 54.3% of patients categorized as HFpEF and 33.1% as HFrEF.
Vital signs varied significantly across patients with preserved, mildly reduced, and reduced EF. Those with HFrEF had higher heart rates and lower systolic blood pressures compared to those with HFpEF, ASD=38.4% and 40.1% respectively. These differences were present both on admission and at discharge. Among patients with HFrEF, 96.8% of patients were prescribed a beta blocker on discharge. In contrast, 65.0% of patients were discharged with an ACEI or ARB and 31.3% with an ARNI. Lastly, 43.2% of patients were prescribed an MRA on discharge. After a median length of stay of 4 [2–6] days, 76.4% of patients were discharged home. SNFs were the second most common discharge location (18.1%), followed by an inpatient rehab facility (4.0%).
Figure 1 shows a bimodal distribution in home-time, such that a substantial proportion of patients spend nearly all their post-discharge time at home, but the second largest group spends very little time at home. Median 30-day and 1-year home-time was 30 [18, 30] and 333 [139, 362] days (Table 2). In the 30-day post-discharge period, 10.1% of patients had no home-time. Furthermore, in the year following discharge, 29.1% of patients spent less than 50% of their time at home and only 22.1% of patients had a full year of home-time. All-cause mortality was 5.7% and 37.0% at 30-days and 1-year respectively. At 1-year, 36.8% of deaths were attributed to cardiovascular causes. Heart failure readmissions were also high at 8.1% and 29.8% at 30-days and 1-year. In total, 24.6% of patients experienced the composite endpoint of all-cause readmission or death at 30 days and 73.3% of patients met the composite endpoint at 1 year.
While home-time overall was significantly correlated with both mortality and readmissions (Table S2), decreases in home-time were predominately driven by time spent in SNFs at short term follow-up with an increasing contribution of mortality over time (Figure 2). Non-cardiovascular death also played a substantial role in lost home-time with a roughly equal contribution from non-cardiovascular and cardiovascular deaths at 1-year follow-up. Notably, Kaplan-Meier curves showed that rates of mortality and readmission were highest in the first few months after the index hospitalization (Figure 3).
Table 3 shows home-time and other outcomes by subgroup with corresponding ASDs in Table S3. Notably, the median 30-day home-time was 30 days across all subgroups. At 1-year follow-up, while there was no significant difference in home-time by sex, ethnicity, or socioeconomic status, home-time differed significantly across age and race (p<0.001 for both). Patients ≥85 years old had a median home-time of 302 [86, 359] days compared to 337 [153, 362] among those 75–84 years old (ASD=20.9%) and 345 [211, 365] in the 65–74 years old group (ASD=32.3%). Black patients also experienced the least amount of home-time (328 [157, 360]) whereas Asian patients had the most (345 [151, 365]), ASD=13.0%. Notably, Black patients had the second lowest 1-year mortality rate at 35.4%, but the highest heart failure and all-cause readmission rate compared to other racial groups (38.5% and 70.5% respectively).
Baseline characteristics of GWTG-HF patients hospitalized at sites participating versus not participating in IMPLEMENT-HF (n=11,509 vs 54,510 respectively) are shown in Table 4. In both cohorts, patients had a median age of 80 years and roughly half of each population was female. The distribution of patients by race differed significantly, ASD = 15.0%. The IMPLEMENT-HF population had a higher proportion of Black patients (14.6% vs. 10.6%) and a lower proportion of white patients (83.4% vs. 86.3%). Other attributes, including comorbidities, vital signs, and laboratory values were similar between groups (ASD<10%), except for A1c, which was higher in the IMPLEMENT-HF group (6.6 [5.8, 7.6] vs. 6.3 [5.7, 7.3], ASD 17.8%) as well as BNP and NT-proBNP which were both lower in the IMPLEMENT-HF group. Prescription rates of ACEI or ARBs and ARNIs were also lower in the IMPLEMENT-HF group (47.8% vs. 50.0% and 9.3% vs. 10.2% respectively). Median home-time among the IMPLEMENT-HF population prior to initiation of any quality improvement measures was 30 [16, 30] and 329 [135, 361] days at 30-days and 1-year post discharge respectively (Table 5). All-cause mortality at 1 year was 37.7% while all-cause readmission was 65.6%.
Discussion
Patients with heart failure had a median of 333 days of home-time in the year following their index heart failure hospitalization, with 29.1% of patients experiencing less than half of their time at home. While SNF stays contributed the most to decreased home-time at 30-day follow-up, mortality played an increasing role over time and was the predominate driver of lost home time at 1-year. Home-time was similarly reduced across sex, ethnicity, and socioeconomic status, although older patients and Black patients experienced significantly greater reductions in 1-year home-time after discharge. All-cause mortality at 1 year was high at 37.0%, with 13.6% attributed to cardiovascular causes. Furthermore, 64.6% of patients had readmissions to the hospital 1-year post-discharge, roughly half of which were for recurrent, worsening heart failure. Baseline characteristics were similar among patients at IMPLEMENT-HF participating sites and those in the broader GWTG-HF cohort. These findings serve as a useful baseline prior to the initiation of IMPLEMENT-HF.
Only a few studies have examined home-time in the context of heart failure hospitalizations and the overall utility of home-time as a clinical endpoint in heart failure is still being evaluated. In a prior GWTG-HF cohort from 2011 to 2014, few patients achieved 100% home-time at 1-year post-discharge.11 Median home-time in this cohort was 322 days at 1-year follow-up. In the updated 2019 to 2021 cohort, we report an increase in median home-time of 11 days. A Swedish study previously found that patients spent roughly 70% of their post-discharge time at home over four years. Those authors also examined trends in home-time from 1992 and 2012 and reported an increase in home-time over the course of the study period.19 The impact of heart failure interventions on home-time as an outcome of interest has also not been well characterized. The CHARM study in 2011 found that patients randomized to candesartan had significantly increased days alive and out of the hospital compared to placebo and suggested that home-time may be a valuable tool for future trials.20 Notably, home-time as defined in this study differs slightly from a measure of days alive and out of the hospital as it also accounts for time spent in SNFs or acute rehabilitation centers.
Variations and potential disparities in home-time across different clinically relevant subgroups remain poorly understood. For instance, while Greene et al. found that male gender and older age were associated with reductions in home-time, they found no significant difference in home-time for Black patients.11 On the other hand, while we found older patients spend relatively less time at home compared to their younger counterparts, there were no significant differences in home-time across sex, ethnicity, or socioeconomic status. We also report significant differences across race with Black patients experiencing the least amount of home-time relative to other racial groups, potentially driven by high readmission rates. Additional studies are needed to further characterize potential disparities in home-time by race and sex.
The outcomes data presented here for home-time, mortality, and readmissions also provide a baseline prior to initiation of IMPLEMENT-HF. The use of home-time as a quality metric offers several advantages. It is patient-centered, can be intuitively understood, and can also be readily calculated from claims data. Additionally, it incorporates time spent in SNFs and rehabilitation centers, which accounts for broader healthcare costs associated with heart failure. However, while home-time encompasses traditional clinical endpoints including mortality and readmissions, its association with other heart failure related performance measures such as use of guideline-directed medical therapy remains unknown. Establishing how quality improvement initiatives, such as IMPLEMENT-HF, impact home-time will be an important next step in better understanding home-time and its overall utility as a hospital quality metric.
Limitations of this study include its observational design as well as its focus on the GWTG-HF cohort and patients enrolled in Medicare, which excludes patients below 65 years of age and overrepresents larger academic centers. Due to limited availability of data on cause of death, cardiovascular mortality was defined as death within 28 days of hospitalization for a primary cardiovascular diagnosis. Although this method has been previously utilized, it may not fully encompass true rates of cardiovascular death.17 Our findings are also limited to the United States and the applicability of home-time in other settings remains unknown. For instance, length of stay or utilization of SNFs may vary substantially in different countries which may confound comparisons of home-time on a global level.21 Available data on guideline-directed medical therapy also exclude sodium-glucose cotranspoter-2 inhibitors given its more recent initiation as a component of guideline directed medical therapy.
Given the limited nature of claims data, we were also unable to assess more specific outcomes related to home-time, such as perceived quality of life at home. There is an urgent need for a practical measure of quality of life for patients with heart failure. Prior studies have attempted to establish the use of quality-adjusted life years for cost-utility analyses in heart failure, but there is no unified approach for this method.22 Studies in other settings, such as after surgery and ischemic stroke, have reported that home-time is positively associated with patient-reported quality of life.4,5 However, additional studies to establish the relationship between home-time and quality of life are needed in the heart failure population.
Conclusions
Among older patients hospitalized with heart failure between 2019 and 2021, median home-time at 1-year post-discharge was 333 days, with older patients over 85 years old experiencing more than one month less of home-time compared to their younger counterparts. Additionally, Black patients had the lowest levels of home-time among various racial groups. This study identifies reduced home-time and high mortality and readmission rates among patients after hospitalization for heart failure and provides a pre-implementation baseline prior to IMPLEMENT-HF. Overall, home-time may serve as a valuable endpoint in heart failure that encompasses both mortality and readmissions, while also adding a unique patient-centered element. Future studies on the impact of health systems interventions, such as IMPLEMENT-HF, on home-time may strengthen its potential as a useful healthcare quality metric in the context of heart failure.
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Dr. Nancy Sweitzer
Cardiology · Advanced Heart Failure & TransplantationWashington University in St. Louisnancys
