raaa mortality risk factors : a 10-year follow-up single center series
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rAAA Mortality Risk Factors : a 10-year follow-up single center series. André Maia Bárbara Moura David João Inês Machado José Silva Liliana Costa. Márcio Mesquita Maria Inês Rocha Isabel Rodrigues Pedro Nóvoa Rui Silva Sara Ramos T20. Index. - PowerPoint PPT PresentationTRANSCRIPT
André MaiaBárbara MouraDavid JoãoInês MachadoJosé SilvaLiliana Costa
Márcio MesquitaMaria Inês RochaIsabel RodriguesPedro NóvoaRui SilvaSara Ramos T20
1. Research Question2. Introduction 3. Main Aims4. Participants and Methods
4.1- Study Participants4.2- Study Design4.3- Variables Description4.4- Confidentiality
5. Results5.1- Summary of the Statistical Analysis 5.2 -Mortality Rates5.3 -Risk Factors Survival Curves5.4 -Complications Crosstable and Chi-Square Test5.5 -Kaplan Meier Survival Curve
6. Discussion7. Conclusion8. References
Index
rAAA: what are the mortality risk factors and the short and
long term mortality rate?
1. Research Question
2. Introduction
The rupture of the aneurism of the infra-renal abdominal aorta:
– very important cause of unheralded deaths in people older than 55 years.
– asymptomatic – with high mortality rates
3.Main Aims• Determining the mortality rates of rAAA patients
admitted in the Angiology and Vascular Surgery Department of HSJ;
• Elaborating a Survival Curve using the Kaplan-Meier method;
• Studying the development of rAAA patients’ condition after surgery;
• Establishing the most common complications caused by surgery;
• Identifying the mortality risk factors associated with ruptured AAA.
4. Participants and Methods
• Target Population– Hospital de São João’s patients.
• Unit of analysis– Each of the patients selected
4.1 Participants and Methods – Study Participants
• Inclusion criteria– Patients admitted to Angiology and Vascular Surgery Department
of HSJ with rAAA in the past 10 years;• Exclusion criteria
– Patients who perished upon hospital arrival, but before entering the operating room;
– Patients whose records lack key information, and whose inclusion would compromise the integrity of the results;
– Patients that lack a minimum number of variables and therefore cannot be used in the analysis;
• Unit of analysis– Each of the patients selected
4.1 Participants and Methods – Study Participants
4.1 Participants and Methods – Study Participants
Data collection: 110 patients
Data collection: 110 patients Data RevisionData Revision Final Count:
109Final Count:
109
AnalysisAnalysis
1 patient excluded
That patient was excluded
because he/she was lacking key
information (Date of Death and
Risk Factors) for the analysis.
4.2 Participants and Methods – Study Design• Classification of the study:
– Retrospective cohort;
• Methods• The first phase consisted in collecting data from the paper
clinical files• Given that several data were missing, a second phase,
regarding research through SAM (“Sistema de Apoio ao Médico”) was required
• Research through SAM still left missing information, so a third phase was employed, which consisted in contacting the surviving patients whose phone number was available
4.3 Participants and Methods – Variables Description
Each patient will be assigned an identification number;The following variables will be collected from the databases: • Identification number• ND• Name• Gender• Date of birth• Phone number• Risk factors:
– Hypertension– COPD– Smoker– Family History– Diabetes– Other risk factors
• Surgery date• ICU exit date• Hospital discharge date• Internment days• Complications:
− Respiratory complications− Cardiac complications− Renal complications
• Aneurism diameter
• Date of death• Death (Dead, Alive)• Timing of death (Operatory,
Hospitalar, After Discharge)• Reintervention date• Age at the Date of the Surgery• Contact Status (Answered, Did
Not Answer, Incorrect Phone Number, Answered but Didn’t Cooperate)
• Age group• Kaplan-Meier Time
4.4 Participants and Methods – Confidentiality
• The voluntary reporting of sensitive outcome data could be compromised unless absolute anonymity was assured;
• The aforementioned identification numbers function as a way to preserve confidentiality;
• Consequently, data is stored in such a way that patients can not be identified, in two different databases:
– The first with NDs, names and contacts;– The second with the other variables.
5. Results
5.1 Summary of the statistical analysis
The data was treated using the SPSS software in order to:1. Determine the mortality rates associated with rAAA in HSJ2. Determine the most common mortality risk factors and
their influence on the mortality rates of rAAA3. Establish the main complications due to the intervention4. Elaborate a Survival Curve using the Kaplan-Meier
estimator method.
5.2 Mortality Rates
Distribution by Gender of Deceased patients
Frequency Valid Percent Cumulative Percent
Male 64 89,9 89,9
Female 7 10,1 100
Total 71 100
Distribution of patients according to age
5.2 Mortality Rates
n = 109
5.2 Mortality Rates
n = 71
5.3 Risk Factors Survival Curves - Hypertension
Time (days) % of surviving patients
1 83
6 65
13 58
31 52
188 39
422 36
Diagnosed
n=57
Time (days) % of surviving patients
9 80
70 40
818 0
Diagnosed
5.3 Risk Factors Survival Curves - COPD
n=5
Time (days) % of surviving patients
1 92
6 76
12 70
26 58
94 51
432 47
Diagnosed
5.3 Risk Factors Survival Curves - Smoking
n=37
Time (days) % of surviving patients
6 75
31 50
Diagnosed
5.3 Risk Factors Survival Curves – Family history
n=4
Time (days) % of surviving patients
1 88
6 71
13 58
24 51
99 32
Diagnosed
5.3 Risk Factors Survival Curves - Diabetes
n=17
5.4 Complications Crosstable and Chi-Square Test
• A Chi-Square was employed in order to find out the level of statistical significance
regarding the relationship between the risk factor smoking and mortality.
• The test returned a value of p=0,195.
• Thus, the null hypothesis was accepted (there is no relation between the two
variables).
• A Chi-Square was employed in order to find out the level of statistical significance
regarding the relationship between the risk factor smoking and mortality.
• The test returned a value of p=0,195.
• Thus, the null hypothesis was accepted (there is no relation between the two
variables).
n= 51 n= 58
5.4 Complications Crosstable and Chi-Square Test
• A Chi-Square was employed in order to find out the level of statistical significance
regarding the relationship between the risk factor smoking and mortality.
• The test returned a value of p=0,013.
• Thus, the null hypothesis was rejected (there is a relation between the two
variables).
• A Chi-Square was employed in order to find out the level of statistical significance
regarding the relationship between the risk factor smoking and mortality.
• The test returned a value of p=0,013.
• Thus, the null hypothesis was rejected (there is a relation between the two
variables).
n= 43 n= 66
5.4 Complications Crosstable and Chi-Square Test
• A Chi-Square was employed in order to find out the level of statistical significance
regarding the relationship between the risk factor smoking and mortality.
• The test returned a value of p=0,988.
• Thus, the null hypothesis was accepted (there is no relation between the two
variables).
• A Chi-Square was employed in order to find out the level of statistical significance
regarding the relationship between the risk factor smoking and mortality.
• The test returned a value of p=0,988.
• Thus, the null hypothesis was accepted (there is no relation between the two
variables).
n= 46 n= 63
5.5 Kaplan Meier Survival Curve
Time (days) % of surviving patients
1 72
7 58
15 51
31 45
188 33
422 31
n= 109
6. Discussion
6. Discussion of the results
• During the study several inconsistencies were found when collecting data:– The data was incorrectly inserted, or missing, leading to wrong assumptions
such as “Non Diagnosed” patients;– Some risk factors are more accessible than others.
• Considering the way that data was collected, hypertensive patients weren’t as easily identified as smokers;
• As for the risk factor “Smoking”, one possible explanation for this situation could be that it was probably easier for contacted people and the aforementioned relatives to remember about the existence of this factor in comparison to the remaining factors.
– Statistical analysis was therefore affected by these misconceptions. • Example: smoking patients showed a slower death rate than those who
were not diagnosed as smokers. Still, we can not assume this dismisses smoking habits as a risk factor for the rupture of the rAAA.
6. Discussion of the results
• A number of factors may have contributed to the bias observed in the results:
– The decreasing quality of data as it approaches the first years of the study, in both the paper and the electronic archives;
– The low size of the sample (n=109);
– The dubious quality of information provided by the relatives of the contacted people (that is, the people who spoke in their place when they were unavailable);
– The low rate of useable phone numbers
7. Conclusion– Firstly, we can conclude that the mortality rates associated with the rupture of AAA are as high
as referenced in the literature, reaching a value of 65,1% of deaths in patients admitted in the Angiology and Vascular Surgery Department of HSJ with rAAA;
– We have also established that the patients’ deaths occurred mostly during their hospital stay, although there was also a high percentage of deaths occurring during the surgery. Those who were released from the hospital survived for a considerable period of time;
– From the complications gathered from the patients’ clinical files, we assembled three general categories (pulmonary, cardiac and renal complications). None was found to be prevalent, although all of them could be tightly related with the high mortality registered;
– Due to a lack of significance in the results of our statistical analysis, we were unable to conclusively correlate the considered risk factors with actual patient mortality;
– Even though we managed to achieve one of our main goals, namely elaborating a Survival Curve, the rest of our objectives were not fully accomplished given the lack of available information.
8. References
• Kubin K, Sodeck GH, Teufelsbauer H, Nowatschka B, Kretschmer G, Lammer J, Schoder M. Endovascular therapy of ruptured abdominal aortic aneurysm: mid- and long-term results http://www.ncbi.nlm.nih.gov/pubmed/18180989?ordinalpos=15&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum
• Qureshi NA, Rehman A, Slater N, Moss E, Shiralkar S, Patel RT, Grimley RP, Jayatunga AP. Abdominal aortic aneurysm surgery in a district general hospital: a 15-years experience http://www.ncbi.nlm.nih.gov/pubmed/17512166?ordinalpos=19&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum