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theses

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 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.

ETD_6632

doi:10.7282/T31G0P66

Ph.D.

Includes bibliographical references

by Abdullah Othman Alamoudi

ETD doctoral

The author owns the copyright to this work.