13

High Resource Use among Adult Congenital Heart Surgery Admissions in Adult Hospitals: Risk Factors and Association with Death and Comorbidities Ami B. Bhatt, MD, FACC, Alefiyah Rajabali, MD, Wei He, MS, and Oscar J. Benavidez, MD, MPP Division of Pediatric/Congenital Cardiology and Adult Congenital Heart Disease Program, Massachusetts General Hospital Heart Center, Harvard Medical School, Boston, Mass, USA ABSTRACT

Objective. Adult hospitals are a common location of adult congenital heart disease (ACHD) admissions, including cardiac surgical admissions. Understanding the patterns and predictors of resource use could aid these institutions by identifying and targeting potentially modifiable determinants of high resource use (HRU). Our objectives were to examine resource use during adult congenital heart surgical admissions in adult hospitals, determine the association of HRU with mortality, and identify risk factors for HRU. Design. Population-based retrospective study We obtained data from the Nationwide Inpatient Sample 2005–2009 and examined ACHD surgical admissions ages 18–49 years (n = 16 231). Outcome Measures. We defined HRU as admissions with >90th percentile for total hospital charges. Results. Despite representing 10% of admissions, HRU admissions accounted for 32% of total charges. HRU admissions had a higher mortality rate (9.7% vs. 1.8%, P < .001). Multivariable analysis demonstrated that HRU is associated with government insurance adjusted odds ratio (AOR) 2.0 (95% confidence interval [CI] 1.6,2.4), emergency admissions AOR 3.9 (95% CI 3.1,4.8), complications AOR 4.2 (95% CI 3.3,5.2), renal failure AOR 1.8 (95% CI 1.4,2.2), congestive heart failure AOR 1.2 (95% CI 1,1.4), surgical complexity risk category-2 AOR 2.0 (95% CI 1.0,3.6), and category-3+ AOR 2.3 (95% CI 1.4,3.8). Conclusions. HRU admissions for adult congenital heart surgery consumed a disproportionate amount of resources and were associated with higher mortality. HRU risk factors included nonelective admissions, government insurance, heart failure, surgical complexity, renal failure, and complications. Complications, if preventable, may be a target for improvement strategies to decrease resource use. Other risk factors may require a broader patient care approach. Key Words. Adult Congenital Heart Disease; Outcomes; Resource Use

Background

A

dvances in both pediatric/congenital heart surgery and intensive care over the past few decades have resulted in increased survival for infants and children with congenital heart disease (CHD). The result of this work has translated to an ongoing increase in the adult CHD (ACHD) population. Presently, there are at least 1.3 million adults with CHD in the United States with an annual growth rate of approximately 5%.1,2 This rapid population growth has been accompanied by an increase in hospital admissions for these patients, which have more than doubled between 1998 and 2005.3 Approximately 20% of these admissions involve cardiac surgery for new diagnoses or to address the sequelae of palliated CHD. © 2014 Wiley Periodicals, Inc.

In addition to having comorbidities associated with prior cardiac surgical procedures, these patients also carry a burden of acquired comorbidities of adulthood. Hospitals caring for these patients must address the interplay of these factors for this complex population. Adult hospitals are a common location of ACHD admissions, including cardiac surgical admissions. As ACHD care continues to evolve, understanding the patterns and predictors of resource use could aid these institutions by identifying modifiable determinants of high resource use (HRU). The objectives of our study were as follows: (1) understand resource use by adults undergoing congenital heart surgery in adult hospitals; (2) identify risk factors for HRU among ACHD surCongenit Heart Dis. 2015;10:13–20

14 gical admissions in adult hospitals; and (3) examine the association of HRU with inpatient death. We hypothesized that HRU would be associated with increased surgical complexity, medical comorbidities, and inpatient death. We also performed an exploratory examination of this adult population admitted to pediatric hospitals. Methods

The study methods were reviewed and approved by the Institutional Review Board of Massachusetts General Hospital.

Data Source We obtained data from 709 adult hospitals using the Nationwide Inpatient Sample (NIS) from January 2005 to December 2009 and examined Adult Congenital Heart Surgical admissions ages 18–49 years. The NIS is a database produced by the Healthcare Cost and Utilization Project that is sponsored by the Agency for Healthcare Research and Quality for the purpose of clinical research. The NIS is the largest publicly available all-payer inpatient care database in the United States, including data on approximately 7–8 million discharges per year, and is a stratified sample designed to approximate a 20% sample of US community (nonfederal, short-term, general, and specialty) hospitals. The NIS contains admission data including age, sex, race, International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis, and procedure codes including comorbidities, insurance type, length of stay, and discharge status (discharged to home, rehabilitation facility, nursing facility, or inpatient death). Data are de-identified and undergo quality and validity checks before inclusion in the database. Study Population Our method of adult congenital heart surgical case selection has been previously described. In summary, we selected admissions ages 18–49 years with ICD-9-CM codes indicating a congenital heart surgical procedure.4–6 We excluded cardiac transplants, extracorporeal membrane oxygenation, ventricular assist devices, transcatheterbased interventions, and pacemaker placement if they were the sole surgical procedure coded. We set our upper age limit to 49 years to minimize inclusion of admissions involving acquired heart disease. Congenit Heart Dis. 2015;10:13–20

Bhatt et al.

Admission Characteristics Characteristics examined included demographics (age, gender, ethnicity, median household income by zip code), hospital characteristics (teaching vs. nonteaching), admission characteristics (weekend vs. weekday admission, elective vs. urgent/emergent admission), and comorbidities (hypertension, diabetes, pulmonary hypertension, chronic renal insufficiency, congestive heart failure, stroke, depression, obesity, alcohol abuse, drug abuse, tobacco use). We categorized payer status into government-sponsored (Medicare, Medicaid, Title V, other government) or nongovernmentsponsored (private, self-pay, other) insurance. Surgical Complexity To attempt to adjust for case mix, we categorized surgical complexity using the risk categories of the Risk Adjustment for Congenital Heart Surgery-1 (RACHS-1) method, a risk-adjustment tool developed to compare in-hospital mortality of congenital heart patients undergoing congenital heart surgery; this method has been previously applied to an ACHD surgical population.6,7 This method assigns congenital heart surgical cases to one of six risk categories based on the presence or absence of specific diagnosis and procedure codes, whereby category 1 has the lowest risk of death and category 6 the highest. In this study, we combined surgical risk categories 4 through 6 because of the paucity cases, and we labeled this category as category 3+ in our multivariate analysis. Cases with combinations of cardiac surgical procedures were placed in the category corresponding to the single highest risk procedure. Resource Use We used total hospital charges as a surrogate for resource utilization and examined the distribution of total hospital charges for ACHD surgery admissions in these adult hospitals. We defined HRU as admissions that exceeded the 90th percentile for total hospital charges for congenital heart surgery admissions. Complications and Death To identify complications, we utilized the society for thoracic surgery (STS) complication short list—a published list of complication diagnoses for congenital heart surgery operations.8 The STS developed a catalogue of complications using a multidisciplinary, international working group. This catalogue also defined certain ICD-9-CM

15

Adult Congenital Heart Surgery Admissions codes as a means of identifying complications occurring during congenital heart surgical admissions.9 Identified complications are not necessarily preventable but represent unwanted clinical events. Inpatient death was examined separately from complications.

Main Outcomes The main outcomes of interest were (1) HRU admissions; (2) complications; and (3) inpatient death. Statistical Analysis We examined the characteristics for ACHD surgery admissions in adult hospitals. We analyzed patient variables and their association to HRU. We estimated the unadjusted association of patient-level characteristics (age, sex, race, genetic syndromes, comorbidities, surgical risk category, and insurance status, inpatient mortality, complication) and admission characteristics (weekend admission, urgent/emergent admission) to HRU admissions using the chi-square test. We also examined the association of HRU with mortality and complications. Multivariate analyses were performed using generalized estimating equation models, which account for the correlation among different admissions from the same hospital. Characteristics with probability value 85% admissions aged

High resource use among adult congenital heart surgery admissions in adult hospitals: risk factors and association with death and comorbidities.

Adult hospitals are a common location of adult congenital heart disease (ACHD) admissions, including cardiac surgical admissions. Understanding the pa...
132KB Sizes 0 Downloads 0 Views