**2.6 Effect of strictly and fully ACR compliant imaging procedures on in-hospital mortality rate**

If compliance level is critical in determining mortality rate, the use of imaging methods in strict compliance with ACR should reduce mortality substantially. However, there can be variations among imaging methods to produce this effect. This aspect was studied, and the data are presented in **Table 7**.

CTA had a very few number of patients reported, and hence zero mortality obtained here is suspect. CT imaging of abdomen and pelvis as well as thoracic regions recorded similar mortality rate in the range of 10.5–12.0. The mortality rate was only 5.3% for US and was the lowest 2.6% for DSA. Based on length of stay, DSA was found undesirable in the earlier discussions. However, mortality rate itself is minimum for DSA, and this may be associated with a short period of hospital stay. All statistical tests were highly significant. Therefore, if ACR compliant procedures are used, DSA method is most effective followed by US in reducing mortality rate.

Earlier, in **Table 8**, mortality rate for different imaging methods (irrespective of ACR compliance) was presented. The mortality rates in both tables agree. Chisquare tests gave highly significant likelihood ratio and linear-by-linear values. Thus the model fitted better with predictors, and the relationship is strongly linear (**Table 8**).

Gamma test and other tests have relatively low negative value indicating a negative relationship between ACR compliance and mortality. Gamma = 0.328, which also indicates a strong degree of inverse correlation. Thus, the higher the compliance, the lower is the mortality rate (**Tables 2–12**).


Accordingly, the odds relationship for ACR compliance with mortality rate is

*Mean effects of increasing compliance with ACR appropriateness criteria on in-hospital mortality rate of aortic*

**Chi-square tests**

*Challenges for Intelligent Data Analysis Methods in Medical Image Analysis during Surgical…*

*Chi-square test results on effect of ACR compliant radiological procedures on frequency of in-hospital mortality*

Usually not appropriate Count 4619 259 4878

May be appropriate Count 32,304 918 33,222

Usually appropriate Count 4 0 4

Total Count 36,927 1177 38,104

Pearson chi-square 206.255a 4 0.000 Likelihood ratio 152.579 4 0.000 Linear-by-linear association 197.995 1 0.000

*Two cells (20.0%) have expected count less than 5. The minimum expected count is 0.12*

**ACR compliance rating Died during**

N of valid cases 38,104

*DOI: http://dx.doi.org/10.5772/intechopen.86711*

*among aortic aneurysm patients in the USA.*

*a*

**Table 8.**

**Table 9.**

**Table 10.**

**37**

**Value df Asymp. sig. (two-sided)**

**hospitalization**

**Did not die Died**

% within ACR compliance rating 94.7% 5.3% 100.0% % within died during hospitalization 12.5% 22.0% 12.8%

% within ACR compliance rating 97.2% 2.8% 100.0% % within died during hospitalization 87.5% 78.0% 87.2%

% within ACR compliance rating 100.0% 0.0% 100.0% % within died during hospitalization 0.0% 0.0% 0.0%

% within ACR compliance rating 96.9% 3.1% 100.0% % within died during hospitalization 100.0% 100.0% 100.0%

**Total**

Ln Odds ð Þ¼�1*:*472 � 0*:*676 � ACR compliance rating

As the equation will result in a negative estimate, odds for mortality decrease when ACR compliance of hospitals increase. Significant Wald test value indicates

no interference of other predictors on the relationship (**Table 13**).

*Effect of ACR compliance levels of hospitals on frequencies of in-hospital mortality.*

Usually not appropriate 5.3 May be appropriate 2.8 Usually appropriate 0

**Compliance level In-hospital mortality percentage**

given by the following equation:

*aneurysm patients in the USA.*

#### **Table 7.**

*The effect of using strictly and fully ACR compliant radiological methods on frequencies of in-hospital mortality of aortic aneurysm patients in the USA.*

*Challenges for Intelligent Data Analysis Methods in Medical Image Analysis during Surgical… DOI: http://dx.doi.org/10.5772/intechopen.86711*


#### **Table 8.**

compliance with ACR guidelines will improve the patient outcome especially on

**2.6 Effect of strictly and fully ACR compliant imaging procedures on**

This aspect was studied, and the data are presented in **Table 7**.

compliance, the lower is the mortality rate (**Tables 2–12**).

The details of the methodology and results are given and are discussed with the

If compliance level is critical in determining mortality rate, the use of imaging methods in strict compliance with ACR should reduce mortality substantially. However, there can be variations among imaging methods to produce this effect.

CTA had a very few number of patients reported, and hence zero mortality obtained here is suspect. CT imaging of abdomen and pelvis as well as thoracic regions recorded similar mortality rate in the range of 10.5–12.0. The mortality rate was only 5.3% for US and was the lowest 2.6% for DSA. Based on length of stay, DSA was found undesirable in the earlier discussions. However, mortality rate itself is minimum for DSA, and this may be associated with a short period of hospital stay. All statistical tests were highly significant. Therefore, if ACR compliant procedures are used, DSA method is most effective followed by US in reducing mortality rate. Earlier, in **Table 8**, mortality rate for different imaging methods (irrespective of

ACR compliance) was presented. The mortality rates in both tables agree. Chisquare tests gave highly significant likelihood ratio and linear-by-linear values. Thus the model fitted better with predictors, and the relationship is strongly linear

Gamma test and other tests have relatively low negative value indicating a negative relationship between ACR compliance and mortality. Gamma = 0.328, which also indicates a strong degree of inverse correlation. Thus, the higher the

**ACR radiological procedures Died during hospitalization Total**

CTA Count 4 0 4

CT: abdomen and pelvis Count 199 27 226

CT: thoracic Count 224 26 250

US Count 4619 259 4878

DSA Count 31,881 865 32,746

Total Count 36,927 1177 38,104

*The effect of using strictly and fully ACR compliant radiological methods on frequencies of in-hospital mortality*

**Did not die Died**

% 100.0% 0.0% 100.0%

% 88.1% 11.9% 100.0%

% 89.6% 10.4% 100.0%

% 94.7% 5.3% 100.0%

% 97.4% 2.6% 100.0%

% within ACR 96.9% 3.1% 100.0%

reducing mortality rate.

(**Table 8**).

**Table 7.**

**36**

*of aortic aneurysm patients in the USA.*

support of scientific evidence.

*Aortic Aneurysm and Aortic Dissection*

**in-hospital mortality rate**

*Chi-square test results on effect of ACR compliant radiological procedures on frequency of in-hospital mortality among aortic aneurysm patients in the USA.*


#### **Table 9.**

*Effect of ACR compliance levels of hospitals on frequencies of in-hospital mortality.*


#### **Table 10.**

*Mean effects of increasing compliance with ACR appropriateness criteria on in-hospital mortality rate of aortic aneurysm patients in the USA.*

Accordingly, the odds relationship for ACR compliance with mortality rate is given by the following equation:

Ln Odds ð Þ¼�1*:*472 � 0*:*676 � ACR compliance rating

As the equation will result in a negative estimate, odds for mortality decrease when ACR compliance of hospitals increase. Significant Wald test value indicates no interference of other predictors on the relationship (**Table 13**).


which imaging methods were more commonly used in the case of ruptured aneurysms? Based on the findings, no specific imaging method was chosen for ruptured aneurysms. However, it is not certain that most of the mortalities occurred in the case of ruptured aneurysms only. It is also not certain that any other imaging method would have reduced mortality of patients with ruptured or intact aneurysms. As is evident from the above results, imaging methods were related to mortality rates: DSA recorded the lowest rate. All other imaging methods recorded

*Challenges for Intelligent Data Analysis Methods in Medical Image Analysis during Surgical…*

The objectives of the study were specifically verified using various tests appro-

Only 5 years' data were included in this study. A more detailed study may need to be done for firm conclusions. Compatibility between NIS data and ICD codes need to be tested by using ICD-10 instead of ICD-9 to verify whether compatibility improves by this. Although several works reported increasing use of CT and MRI, this was not reflected in a data set as recent as 2008–2012. Similarly, increasing use of EVAR compared to OAR was also not reflected. This needs further investigation. How far probabilistic estimates of mortality based on predictors will be closer to actual figures is not clear either from published works or from this study. This aspect needs further study by developing such equations and comparing actual with

There is enough evidence that hospitals are less than fully compliant with ACR appropriateness criteria. However, their number is not known. A survey of US hospitals to evaluate numbers of fully compliant, partially compliant and noncompliant hospitals needs to be done. The latter two need to be persuaded to fully

Recognizing the high mortality rates in certain aneurysm conditions, factors related to this were examined. Imaging methods have an important role in diagnosis and treatment interventions. ACR has published appropriateness criteria for diagnostic imaging. It was contended that if hospitals followed ACR guidelines, it would improve diagnosis and in turn intervention procedure also. The research was aimed at this aspect to develop predictors for mortality due to imaging methods and intervention procedures. Patient characteristics like age, gender, race, comorbidities and insurance type for medical reimbursement and hospital contexts like size, location, geographical region, type and admission types were included as variables for the study. The basic variables were four imaging methods and their combinations with EVAR and OAR upon which the patient characteristics and hospital contexts were superimposed. NIS data for the period of 2008–2012 from more than 4300 US hospitals were used. After prescribed data cleaning procedures, net sample size of 38,263 patients was obtained for detailed study. Apart from descriptive

priate to the specific objective. The objectives were to establish that imaging methods had distinct influence on mortality rates, to compare the two intervention procedures in interaction with the imaging methods, to evaluate the impact of compliance with ACR guidelines on mortality rates, to examine the scope of using any patient factor or hospital context as predictors of mortality rates and to assess which imaging method is associated with mortality rate as affected by any of the significant predictors. The study relied on diagnosis and procedure of only the ICD-9 coding registered in NIS data set. NIS data does not include all the sophisticated diagnostic imaging procedure codes. Differentiation of pre- and post-operative imaging is not available in ICD-9 codes and is not indicated in NIS data also. This

study was limited to the study of most common aneurysms and not all.

higher than 3.4%.

*DOI: http://dx.doi.org/10.5772/intechopen.86711*

estimates.

**4. Conclusions**

**39**

comply with the ACR criteria.

#### **Table 11.**

*Chi-square test results on effect of ACR compliance levels of hospitals on frequencies of in-hospital mortality of aneurysm patients in the USA.*


#### **Table 12.**

*Gamma test results on frequencies of in-hospital mortality of aneurysm patients as affected by ACR compliance levels of hospitals in the USA.*


#### **Table 13.**

*ACR compliance rating and various constants values.*
