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224 Pages·2015·3.13 MB·English

THE INFLUENCE OF DIFFERENT DIAGNOSTIC IMAGING AND
INTERVENTIONAL REPAIR TECHNIQUES ON MORTALITY RATE IN
AORTIC ANEURYSM PATIENTS
By
Abdullah Othman Alamoudi

A Dissertation Submitted to
Rutgers Biomedical and Health Sciences
School of Health Related Professions
Department of Health Informatics
[In partial fulfillment of the requirements for the Degree of Doctor of Philosophy]
June 2015
THE INFLUENCE OF DIFFERENT DIAGNOSTIC IMAGING AND
INTERVENTIONAL REPAIR TECHNIQUES ON MORTALITY RATE IN AORTIC
ANEURYSM PATIENTS
BY
Abdullah Othman Alamoudi

Dissertation Committee:
Shankar Srinivasan, Ph.D., Advisor
Syed S. Haque, Ph.D., PhD., Department Chair
Frederick Coffman, Ph.D.

Approved by the Dissertation Committee:
Date

Date

Date
Copyright © Abdullah O Alamoudi 2015
DEDICATION
This work is dedicated to my lovely parents, Asma Alamoudi and Othman Alamoudi, my
mam demonstrated what it meant to be strong and independent man. She inspired me to
pursue a career in healthcare and was beaming with pride upon my acceptance into the
Doctoral program. My dad I am grateful for your continuous support and what you taught
me has helped me achieve this milestone, for which I am forever thankful.
I also dedicate this work to my lovely brothers Mohammed, Zohair, and Abdulrahman,
your presence in my life bringing joy and happiness to my life and always making me
proud as a brother to have you all in my life, your love, advices and support help throughout
my life.
Furthermore, my dissertation is dedicate to my family and friends, especially my dear ankle
Omar Alamoudi I would not be who I am today without your support and helped
throughout my study journey. Also, thank you to dear ankle Abdullah Alamoudi, my dear
cousin Mohammed Hashem Alamoudi, my dear friends Basim Alzhrani, James Gnge,
Dr.Raid Alhazmi, Dr. Rafat Mohtasb, Dr. Mohammed Alhazmi, Dr. Mohammed
Almoanas, Dr. Mohasen Alamohsen. Your encouragement and believe in my abilities
motivated me during challenging times to complete this degree.
An equal dedication goes to Sinem Ozer, your support and motivational words, have
positively changed my life and allowed me to attain my personal and future goals and be
successful in my endeavors.
Last but not least, I would like to dedicate this dissertation to all those who have positively
impacted my life and helped me at some point of my life.
ACKNOWLEDGMENTS
During the completion of my degree I have been fortunate to have had the opportunity to
teach from many knowledgeable faculty members. First, I would like to thank my creator
and also Dr.Sayed haque the chairman of the department who provided me with invaluable
advice that has continued beyond my years and I’m so grateful.
Throughout the completion of my dissertation my committee has provided me with
continuous support. Dr.Shankar, my Chair, has tirelessly provided mentorship throughout
my studies and work at the State University of New Jersey, Rutgers. My word cannot
describe my gratitude and thankfulness for his kind spirit and dedication to my career
development. I look to Dr.Shankar with great admiration. His clinical expertise paired with
his genuine passion for quality improvement and patient safety has been an inspiration for
continuing research in this area.
I would like to thank the member of my committee Dr.Frederick Coffman for his useful
advice during my dissertation process. I would like also to thank Dr.Mital for the
abundance of support has given throughout my study. He always made time to help me
though challenges and always knew the right time to challenge me. I am thankful for
Dr.Mital persistence to help me reach my fullest potential. I have had the pleasure of
working with all of you during this journey. It has been an absolute honor to have worked
so closely with each of the members of my dissertation committee.
TABLE OF CONTENTS

ABSTRACT ...................................................................................................................................... i
LIST OF FIGURES ........................................................................................................................ iii
LIST OF TABLES .......................................................................................................................... iv
LIST OF ABBREVIATIONS ....................................................................................................... viii
CHAPTER I: INTRODUCTION ..................................................................................................... 1
1.1 Background of the Problem ............................................................................................. 1
1.2 Statement of the Problem ............................................................................................... 10
1.3 Research Purpose, Specific Aims and Hypotheses ........................................................ 11
1.4 Significance of Study ..................................................................................................... 13
CHAPTER II: LITERATURE REVIEW ...................................................................................... 15
2.1 Aneurysm Overview ...................................................................................................... 15
2.2 Symptoms ...................................................................................................................... 15
2.3 Aneurysm Classifications and Types ............................................................................. 16
2.4 Aortic Aneurysm ............................................................................................................ 19
2.4.1 Thoracic Aortic Aneurysm (TA) and Thoracico-abdominal Aortic Aneurysm
(TAA) 19
2.4.2 Abdominal Aortic Aneurysm (AAA) .................................................................... 21
2.4.3 Small Abdominal Aortic Aneurysm (AAA) .......................................................... 23
2.4.4 Infra-renal AAA ..................................................................................................... 24
2.4.5 TA/TAA AND AAA Occurrence .......................................................................... 25
2.5 Aneurysm Diameter ....................................................................................................... 26
2.6 Prevalence and Epidemiology ........................................................................................ 26
2.7 Risk Factors and Prediction ........................................................................................... 27
2.8 GLASGOW Aneurysm Risk Scoring System ............................................................... 28
2.9 Patient Classifications .................................................................................................... 30
2.9.1 Age ......................................................................................................................... 32
2.9.2 Gender .................................................................................................................... 32
2.9.3 Race........................................................................................................................ 34
2.10 Hospital Contexts and Mortality .................................................................................... 35
2.10.1 Hospital Contexts and Patient Classifications........................................................ 36
2.10.2 Geographical and Hospital Volume ....................................................................... 37
2.11 Interventional Aneurysm Repair Procedures ................................................................. 38
2.11.1 Endovascular Aortic Repair (EVAR) .................................................................... 39
2.11.2 Endovascular Aortic Repair (EVAR) and Open Aortic Repair (OAR)
Comparison ............................................................................................................................ 39
2.11.3 Long Term Survival ............................................................................................... 47
2.12 Medical Imaging Modalities .......................................................................................... 47
2.12.1 Computed Tomography (CT)................................................................................. 54
2.12.2 Computed Tomography Angiography (CTA) ........................................................ 55
2.12.3 Magnetic Resonance Imaging (MRI) ..................................................................... 58
2.12.4 Magnetic Resonance Angiography (MRA) ........................................................... 60
2.12.5 Ultrasound Scan (US) ............................................................................................ 60
2.12.6 Digital Subtraction Angiography (DSA) ............................................................... 62
2.12.7 Screening Programs to Prevent Rupture and Mortality ......................................... 63
2.13 Diagnostic Imaging Guidelines ...................................................................................... 67
2.13.1 Hospital Compliance of ACR Guideline on Abdominal Aortic Aneurysm ........... 70
2.13.2 Cost Effectiveness .................................................................................................. 72
2.14 Summary of Literature Review ...................................................................................... 76
CHAPTER III: MATERIALS AND METHODS ......................................................................... 79
3.1 Overview ........................................................................................................................ 79
3.2 Objectives, Variables and Statistical Analysis Procedures ............................................ 80
3.3 Data Availability ............................................................................................................ 81
3.4 NIS Dataset .................................................................................................................... 81
3.5 NIS Sampling Framework ............................................................................................. 86
3.6 Disease and Procedures Coding ..................................................................................... 87
3.7 ACR Guideline Compliance .......................................................................................... 89
3.8 Statistical Modelling Analysis ....................................................................................... 91
3.9 Research Design............................................................................................................. 92
CHAPTER IV: RESULTS OF DATA ANALYSIS ...................................................................... 94
4.1 Introduction .................................................................................................................... 94
4.2 Data Filtering Process .................................................................................................... 94
4.3 Result of Descriptive Statistic and Frequencies ............................................................. 96
4.3.1 Aortic Aneurysm Distribution According to Types ............................................... 96
4.3.2 Aneurysm Repair Frequencies ............................................................................... 97
4.3.3 Frequencies of Aneurysm Diagnostic Imaging by Different Modalities ............... 98
4.3.4 Patient Characteristics .......................................................................................... 100
4.3.5 Hospital Contexts ................................................................................................. 113
4.3.6 Medical Imaging Modalities Associated with Interventional Aneurysm Repair for
Aortic Aneurysm Types ....................................................................................................... 120
4.3.7 Mean Length of Stay and Imaging Procedure...................................................... 123
4.4 Achievement of Objectives of This Study ................................................................... 126
4.5 Summary of Chapter IV Results .................................................................................. 170
CHAPTER V: DISCUSSION AND STUDY LIMITATION ..................................................... 173
CHAPTER VI: SUMMARY, SUGESSTION FUTURE RESEARCH ....................................... 187
REFERENCES ............................................................................................................................ 190
ABSTRACT

Among the several factors related to high mortality, imaging methods and intervention
procedures could be important. American College of Radiologists (ACR) prescribed some
appropriateness guidelines for diagnostic imaging. Not complying with them fully or
partially may also be a mortality factor. The present study was undertaken to investigate
these aspects.
NIS data for the period of 2008-2012 using ICD-9 codes were obtained for 6 types of
aneurysms- intact and ruptured Abdominal Aortic Aneurysm (AAA), Thoracic Aneurysm
and Thoracio-Abdominal Aneurysm; four imaging methods: Computerized Tomography
(CT), Magnetic Resonance Imaging (MRI), Ultrasound (US) and Digital Subtraction
Angiography (DSA) as diagnostic imaging methods; EVAR or OAR as the intervention
procedures; patient characteristic factors of age, gender, race, comorbidities and insurance
type; and hospital context factors of size, location and teaching status, region and admission
type. The dependent variables were total, died in hospital and did not die frequencies
patients. Data on 38263 patients were obtained from this search from more than 4,300
participating hospitals. The data were analyzed using SPSS22 software using descriptive
statistics, ANOVA, logistic multiple regression test, Chi square test, McNemar test and
Gamma test.
AAA was most frequent (73.4%) followed by TA (20.6%). All ruptured aneurysms
together constituted only about 3.4%. Very few cases of ruptured aneurysms affected
precise evaluation of high mortality due to rupture. About 63% aneurysms were repaired
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using OAR and only 23% cases were treated by EVAR. Increasing popularity of EVAR
was not reflected in this data. Among the imaging methods, DSA was used in about 86%
cases and US was used in 13% cases.
Always DSA was highest followed by US, CT and MRI in the decreasing order. Higher
numbers of younger age group patients (65-79) were imaged using DSA and US. More
numbers of older patients were imaged using CT and MRI (70-84). Whites, blacks and
Hispanics were the highest three percentages among the races. About 70% of all aneurysm
patients were males. Most patients were covered by Medicare or Medicaid or private
insurance. Only 2% patients met their expenses on their own. Among comorbidities,
hypertension, diabetes, heart failure and anaemia were more common.
All objectives were achieved. Effect of imaging methods and its interaction with
interventional procedures in reducing in-hospital mortality rates were demonstrated.
Compliance with ACR appropriateness helps to reduce mortality rates. Age groups and
comorbidities of patient characteristics influenced mortality rate more effectively. Linear
logistic equations for odds for dying against imaging methods, its interaction with
intervention procedures, ACR compliance level, patient age and comorbidities and some
hospital contexts were developed. Limitations of this research and future scope of research
have also been discussed.

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LIST OF FIGURES

FIGURE 1: NUMBER OF PEOPLE AFFECTED BY AORTIC ANEURYSM IN DIFFERENT STATES OF USA ................ 1
FIGURE 2: AORTIC ANEURYSM INCIDENCE PER 100,000 POPULATION IN DIFFERENT STATES OF USA ............ 2
FIGURE 3: SIX DIMENSIONS OF HEALTH CARE QUALITY 4. .............................................................................. 4
FIGURE 4: INPATIENT VERSUS OUTPATIENT SURGERIES IN USA HOSPITALS DURING 2012 5. ......................... 5
FIGURE 5: RATE OF CARDIAC STENT PROCEDURES DURING 1999-2009 8. ........................................................ 9
FIGURE 6: DATA FROM HOSPITALS HAVE PARTICIPATED ACROSS THE UNITED STATES. .............................. 79
FIGURE 7: SUB-CATEGORIZATION OF DATA ELEMENTS USED IN THIS STUDY ............................................... 83
FIGURE 8: SCHEMATIC PROCESS OF SELECTING THE SIX AORTIC ANEURYSM TYPES IN THIS STUDY ............ 92
FIGURE 9: SCHEMATIC EXPLANATION OF SAMPLES SELECTION AND VARIABLES IN THIS STUDY .................. 93
FIGURE 10: DATA FILTRATION METHODS USED IN THE STUDY WITH IN-HOSPITAL MORTALITY OUTCOME. . 95
FIGURE 11: FREQUENCIES DISTRIBUTION OF DIFFERENT TYPES OF AORTIC ANEURYSMS AMONG US
PATIENTS............................................................................................................................................... 97
FIGURE 12: DISTRIBUTION OF INTERVENTIONAL AORTIC ANEURYSM REPAIR IN US HOSPITAL BETWEEN 2008
AND 2012 .............................................................................................................................................. 98
FIGURE 13: DISTRIBUTION OF DIAGNOSTIC IMAGING MODALITIES IN US HOSPITAL BETWEEN 2008 AND 2012
.............................................................................................................................................................. 99
FIGURE 14: AGE GROUPS OF POPULATION AFFECTED BY AORTIC ANEURYSMS .......................................... 102
FIGURE 15: THE AGE DISTRIBUTION OF AORTIC ANEURYSMS IN US POPULATION ...................................... 102
FIGURE 16: NIS RACE DISTRIBUTION BETWEEN 2008 AND 2012. ................................................................ 106
FIGURE 17: NIS GENDER DISTRIBUTION BETWEEN 2008 AND 2012. ............................................................ 107
FIGURE 18: NIS MEDICAL INSURANCE TYPE DISTRIBUTION OF AORTIC ANEURYSM PATIENTS. ................. 109
FIGURE 19: COMORBIDITIES ARE COMMONLY ASSOCIATED WITH AORTIC ANEURYSM ............................... 110
FIGURE 20: NIS HOSPITAL BED SIZE DISTRIBUTION OF AORTIC ANEURYSM PATIENTS. ............................. 114
FIGURE 21: HOSPITAL LOCATION AND TEACHING STATUS DISTRIBUTION BETWEEN 2008 AND 2012. ......... 115
FIGURE 22: NIS HOSPITAL REGION DISTRIBUTION OF AORTIC ANEURYSM PATIENTS FROM 2008 AND 2012.
............................................................................................................................................................ 116
FIGURE 23: ADMISSION TYPE OF AORTIC ANEURYSM PATIENTS IN US HOSPITALS. .................................... 117
FIGURE 24: IMAGING TECHNIQUES ASSOCIATED WITH INTERVENTIONAL REPAIR IN US HOSPITAL BETWEEN
2008 AND 2012. ................................................................................................................................... 122

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