Effect of the Diagnosis of Inflammatory Bowel Disease on Risk-Adjusted Mortality in Hospitalized Patients with Acute Myocardial Infarction, Congestive Heart Failure and Pneumonia
July
Effect of the Diagnosis of Inflammatory Bowel Disease on Risk-Adjusted Mortality in Hospitalized Patients with Acute Myocardial Infarction, Congestive Heart Failure and Pneumonia
Eli D. Ehrenpreis 0 1
Ying Zhou 0 1
Aimee Alexoff 0 1
Constantine Melitas 0 1
0 Center for the Study of Complex Diseases, NorthShore University HealthSystem , Evaston, Illinois , United States of America
1 Editor: John Green, University Hospital Llandough , UNITED KINGDOM
Measurement of mortality in patients with acute myocardial infarction (AMI), congestive heart failure (CHF) and pneumonia (PN) is a high priority since these are common reasons for hospitalization. However, mortality in patients with inflammatory bowel disease (IBD) that are hospitalized for these common medical conditions is unknown.
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Data Availability Statement: The data is contained
within the manuscript and its Supporting Information
files.
Funding: This study was funded in part by a grant by
the Keyser Family Fund to the Center for the Study of
Complex Diseases. The funders had no role in study
design, data collection and analysis, decision to
publish, or preparation of the manuscript.
Competing Interests: The authors have declared
that no competing interests exist.
Methods
A retrospective review of the 2005–2011 National Inpatient Sample (NIS), (approximately a
20% sample of discharges from community hospitals) was performed. A dataset for all
patients with ICD-9-CM codes for primary diagnosis of acute myocardial infarction,
pneumonia or congestive heart failure with a co-diagnosis of IBD, Crohn’s disease (CD) or ulcerative
colitis (UC). 1:3 propensity score matching between patients with co-diagnosed disease vs.
controls was performed. Continuous variables were compared between IBD and controls.
Categorical variables were reported as frequency (percentage) and analyzed by Chi-square
tests or Fisher’s exact test for co-diagnosed disease vs. control comparisons. Propensity
scores were computed through multivariable logistic regression accounting for
demographic and hospital factors. In-hospital mortality between the groups was compared.
Results
Patients with IBD, CD and UC had improved survival after AMI compared to controls. 94/
2280 (4.1%) of patients with IBD and AMI died, compared to 251/5460 (5.5%) of controls,
p = 0.01. This represents a 25% improved survival in IBD patients that were hospitalized
with AMI. There was a 34% improved survival in patients with CD and AMI. There was a
trend toward worsening survival in patients with IBD and CHF. Patients with CD and PN had
improved survival compared to controls. 87/3362 (2.59%) patients with CD and PN died,
compared to 428/10076 (4.25%) of controls, p < .0001. This represents a 39% improved
survival in patients with CD that are hospitalized for PN.
Conclusion
IBD confers a survival benefit for patients hospitalized with AMI. A diagnosis of CD benefits survival in patients that are hospitalized with PN.
Introduction
The Centers for Medicare & Medicaid Services (CMS) and Hospital Quality Alliance (HQA)
release quarterly reports on mortality of hospitalized patients with acute myocardial infarction
(AMI), congestive heart failure (CHF) and pneumonia (PN) [
1–2
]. 30-day mortality rates for
AMI, CHF, and PN are also reported by CMS. Mortality indicators have been developed by the
Agency for Health Research on Quality (AHRQ). The diagnoses of AMI, CHF and PN have
become a primary focus of these agencies, since these conditions are common reasons for
hospital admission among older adults [3,4]. Reporting of risk-standardized mortality is intended
to enhance accountability of collected data by considering patient risk as well as
hospital-specific effects (i.e. the risk of mortality for individual hospitals). The overall goal of measuring
risk-standardized mortality is advancement of patient outcomes [5–6].It is intuitive that the
presence of preexisting co-morbidities may have a negative impact on outcomes in patients
that are hospitalized for medical conditions. This effect has been explored in detail in patients
with AMI and those undergoing coronary bypass grafting (CABG) by Vaughn, et al [7]. Of
interest, their group defined co-morbidities as non-paradoxical (preexisting conditions that
worsen mortality in hospitalized patients) or paradoxical (preexisting conditions that improve
mortality in hospitalized patients). Examples of paradoxical co-morbidities found to improve
30 day survival after AMI include hypertension, diabetes, and obesity. There are a variety of
potential explanations for the occurrence of paradoxical co-morbidities [8–9].
Prior studies suggest that patients with IBD, particularly Crohn’s Disease (CD), are at higher
risk for thromboembolic disorders, coronary artery disease and AMI [10–12]. PN has also
been found to occur more commonly in patients with IBD compared to those in the general
population [13–14]. However, there has been limited prior evaluation of outco (...truncated)