systematic review: accuracy of fetal echocardiography final presentation introdução à medicina...

Systematic review:

Accuracy of fetal echocardiography

Systematic review:

Accuracy of fetal echocardiography

Final presentation

Introdução à Medicina

Anual project

2005/2006

Class 22

1. Introduction

• Fetal Echocardiography is the only way we can study fetal heart.

• This technique requires the use of high-resolution ultrasound equipment with M-mode, pulsed and colour Doppler imaging capabilities ( pictures 1, 2, 3 and 4) [1].

• Congenital heart disease has been reported to occur in 8/1000 live births. Prenatal diagnosis of congenital heart disease is crucial to optimal obstetric and neonatal care. In utero identification of congenital heart disease allows a variety of treatment options to be considered, including delivery at an appropriate facility, termination of pregnancy and in some cases in utero therapy.

Systematic review: accuracy of fetal echocardiography Class 22

Picture 1:Picture 1: M- M-modemode

Picture 2:Picture 2: Pulsed Pulsed DopplerDoppler

Picture 3:Picture 3: Colour Colour DopplerDoppler

Picture 4:Picture 4: Power Power DopplerDoppler

[1]:Julia A. Drose, “Fetal Echography”, W.B. Saunders CompanyLindsey Allan, Lisa K Hornberger, Gurleen Sharland, “Text Book of fetal cardiology”, GMM

1. Introduction (cont.)

• Sensitivity and specificity are the most widely used statistics to describe a diagnostic test.

sensitivity is the probability of a positive test among patients with disease;

specificity is the probability of a negative test among patients without disease.

• OBJECTIVE:

Evaluate the accuracy of fetal echocardiography, in prenatal diagnosis of cardiac anomalies.

• Databases selected:

Pubmed

SCOPUS


Sensitivity and specificity values

2.1 Articles search

2.2 Abstracts analyse

2.3 Full article search

2.4 Quality criteria

2.5 Descriptive statistics

2.6 Homogeneity/Heterogeneity

2.7 Flowchart – planification of the tasks

2.1 Articles search

2.2 Abstracts analyse




2.6 Homogeneity/Heterogeneity

2.7 Flowchart – planification of the tasks

2. Methods

Group of tasks that the systematic review includes;


2.1 Articles search (Pubmed)


#1 ((((((("sensitivity and specificity"[All Fields] OR "sensitivity and specificity/standards"[All Fields]) OR

"specificity"[All Fields]) OR"screening"[All Fields]) OR "false positive"[All Fields]) OR "false negative"[All Fields]) OR "accuracy"[All Fields])

OR ((("predictive value"[All Fields] OR "predictive value of tests"[All Fields]) OR "predictive value of

tests/standards"[All Fields]) OR "predictive values"[All Fields]) OR "predictive values of tests"[All Fields]))

#2(("reference value"[All Fields] OR "reference values"[All Fields]) OR "reference values/standards"[All Fields])

#3((((((((((("roc"[All Fields] OR "roc analyses"[All Fields]) OR "roc analysis"[All Fields]) OR "roc and"[All Fields])

OR "roc area"[All Fields]) OR "roc auc"[All Fields]) OR "roc characteristics"[All Fields]) OR "roc curve"[All Fields]) OR "roc curve method"[All Fields]) OR "roc curves"[All Fields]) OR "roc estimated"[All Fields]) OR "roc evaluation"[All Fields])

((((( #1 OR #2) OR #3) OR "likelihoodratio"[All Fields]) AND notpubref [sb]) AND "human"[MeSH Terms]) The final sentence will be:

(((( #1 OR #2) OR #3) OR "likelihoodratio"[All Fields]) AND notpubref [sb])

This research ensures that we can find all the articles related to tests of sensitivity and specificity.

To adapt it to the subject of this work we added:AND ("echocardiography" OR echocardiography[MeSH Terms]) AND (Heart Defects, Congenital[MeSH

Terms] OR "cardiac anomalies"

Our strategy:Our strategy: We divided in parts the sentence from the article used [2] for the We divided in parts the sentence from the article used [2] for the search :search :

[2] “BMC Medical Research Methodology”,Conducting systematic reviews of diagnostic studies: didactic guidlines (www.biomedcentral.com/1471-2288/2/9 )

1044 articles found1044 articles found

http://www.biomedcentral.com/1471-2288/2/9

We adapted the query used in Pubmed to the SCOPUS software, by making the following changes:

substitute All Fields and Mesh Terms for ALL.

Inicial Query:

(((((((((((ALL("sensitivity and specificity") OR ALL("sensitivity and specificity/standards")) OR ALL("specificity")) OR ALL("screening")) OR ALL("false positive")) OR ALL("false negative")) OR ALL("accuracy")) OR (((ALL("predictive value") OR ALL("predictive value of tests")) OR ALL("predictive value of tests/standards")) OR ALL("predictive values")) OR ALL("predictive values of tests"))) OR (ALL("reference value") OR ALL("reference values") OR ALL("reference values/standards"))) OR ((((((((((((ALL("roc") OR ALL("roc analyses")) OR ALL("roc analysis")) OR ALL("roc and")) OR ALL("roc area")) OR ALL("roc auc")) OR ALL("roc characteristics")) OR ALL("roc curve")) OR ALL("roc curve method")) OR ALL("roc curves")) OR ALL("roc estimated")) OR ALL("roc evaluation")))) AND (("echocardiography" OR ALL("echocardiography")) AND ALL(congenital heart defects) OR ALL("cardiac anomalies")))

subsequent additions:


2.1 Articles search (SCOPUS)

AND ( EXCLUDE(PUBYEAR,2006) )

AND (EXCLUDE(SUBJAREA, "VETE"))

AND ALL(Fetus OR Fetuses OR fetal OR prenatal OR antenatal OR perinatal OR embryonic OR pregnancy OR pregnant OR pregnancies OR obstetric OR gestation OR utero OR feto OR fetos OR pré-natal OR gravidez OR grávida OR gestação OR útero)

810 articles 810 articles foundfound

• SEARCH RESULTS

• Each article was submitted to analyses, to evaluate how it can be relevant to our study


Pubmed 1044 articles

SCOPUS 810 articles

1854 articles

2.1 Articles search (cont)

• We used the program EndNote to compare the articles from Pubmed with the articles from SCOPUS. We had removed 158 articles that were repeated.

1854 – 158 = 1696

1696 1696 articlesarticles TOTAL

• INCLUSION/EXCLUSION CRITERIA:

We selected articles which fullfil the following criteria:

To be applied to humans, fethus, in particular;

Refer the echocardiography as the only diagnostic test used;

Cardiac anomalies as subject of study;

Articles with their abstracts available;

Sensitivity and specificity studies;

Language: english or portuguese.

Each article was reviewed by two students; in cases of discordance prevailed the decision of a third reviewer;


2.2 Abstract’s analyse

157 (Pubmed) + 91 (SCOPUS) articles

included


• The full articles were searched, according to the following order:


1st: Through Web: Pubmed; SCOPUS; Google;

2nd: Faculty Library; which indicated us in which department was the article available.

3rd: Contact autor(s) by e-mail;

14 articles included


• STARD checklist [3]:

– It is a 25 item document that classifies articles quality, based on the total items fulfiled:

– If an article has a caracteristic we atribute 1 point, if not we atribute 0 points. Finally, we added up all the points and verificate the result

obtained.


[3] “Towards complete and Accurate Reporting of Studies of diagnostic Accuracy: The STARD Initiative” – Patrick M. Bossuyt et al; available on http/www.annals.org.

• Metadisc was the statistical software selected;• We analysed the following information:

True PositivesTrue NegativesFalse PositivesFalse Negatives

Positive predicted valueNegative predicted value

Likelihood ratio

The software designed a Forest Plot,

indicating the sensitivity and specificity values of the diagnostic test in study.



2.6 Homogeneity vs Heterogeneity

It is important to know if the variance found is or is not the result of the variability of the sample.

• STRATEGY:

a) evaluate the heterogeneity’s degree; b) find and explore the causes c) interpret these results in the context of the problem;

Chi-square testChi-square test: a statistical software which analyses the degree of homogeneity/heterogeneity, by calculating the p value:


If p > 0,05 Homogeneous studyIf p < 0,05 Heterogeneous study

(95% confidence interval)

2.7 Flowchart

This flowchart is a resume of our methods.


3. Results


•QUALITY RESULTS

PMID TOTAL

12124694 14

16250307 14

12100413 16

8826811 15

15320552 16

1571648 18

1595882 17

12235719 19

10325811 13

7778627 17

1571638 10

12235719 19

3685364 15

12231598 18

Tab1: quality’s degree of the articles included in our study. This result refers to a scale from 0 to 25 as already seen in Methods

•SENSITIVITY RESULTS

Graph1: studies with high sensitivity

Graph2: studies with low sensitivity


•SPECIFICITY RESULTS

Graph 3: Specificity

4. Conclusion/Discussion


There was a great variance of quality among the articles found. The quality mean – 15,8 (out of 25) – reveal that these articles have a reasonable classification in terms of quality.

Different values of sensitivity

Different populationsDifferent methods

•Four-chamber view

•Extended Echocardiography

•High risk population

•Low risk population

Low sensitivity values

Low sensitivity valuesHigh sensitivity values

High sensitivity values

All the articles had a very high specificity value



Nowadays…

… four-chamber view in low risk population

… extended echocardiography in high risk population

However…

… most neonates with congenital heart disease are born in women without any previous known risk factors

… four-chamber less expensive

less human resources

… high risk population the sensitivity tends to be higher with both techniques



We are able to conclude…

… the four-chamber view may be enough to detect cardiac anomalies in high risk population

… the four-chamber view appears to be ineffective in low risk population as a screening method

… the screening technique to be used should be the extended echocardiography.

In the future, it would be useful to investigate a way to make the extended echocardiography affordable so it can

be used as a screening method

Sofia PinaTânia AbreuTânia AfonsoTiago Rito


Class 22:Tiago CardosoTelma SantosTeresa BastosVítor FerreiraZoe Costa

systematic review: accuracy of fetal echocardiography final presentation introdução à medicina...

Documents

likelihoodratioall fields

accuracyall fields

specificitystandardsall

rocall fields

roc curvesall fields

roc curveall fields

roc estimatedall fields

roc analysisall fields