Emergency (****); * (*): *-*


  
  
 
  

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1 Emergency (2016); 4 (1): 1-10 

REVIEW ARTICLE 
 

 

Screening Performance Characteristic of Ultrasonography and Radiography 

in Detection of Pleural Effusion; a Meta-Analysis  
 

Mahmoud Yousefifard1, Masoud Baikpour2, Parisa Ghelichkhani3, Hadi Asady4, Kavous Shahsavari Nia5,  

Ali Moghadas Jafari6, Mostafa Hosseini7, 8*, Saeed Safari9 
 

1. Department of Physiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.  
2. Department of Medicine, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. 

3. Department of Intensive Care Nursing, School of Nursing and Midwifery, Tehran University of Medical Sciences, Tehran, Iran. 
4. Department of Occupational Health Engineering, Faculty of Public Health, Tehran University of Medical Sciences, Tehran, Iran. 

5. Road Traffic Injury Research Center, Tabriz University of Medical Sciences, Tabriz, Iran. 
6. Department of Emergency Medicine, Bushehr University of Medical Sciences, Bushehr, Iran. 

7. Sina Trauma and Surgery Research Center, Tehran University Medical Sciences, Tehran, Iran. 
8. Department of Epidemiology and Biostatistics, school of Public Health, Tehran University of Medical Sciences, Tehran, Iran. 

9. Department of Emergency Medicine, Shohadaye Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran. 
 

*Corresponding Author: Mostafa Hosseini, Department of Epidemiology and Biostatistics School of Public Health, Tehran University of Medical Sciences , 
Poursina Ave, Tehran, Iran; Email: mhossein110@yahoo.com; Tel: +982188989125; Fax: +982188989127. 

Received: June 2015; Accepted: August 2015 
 

Abstract 

Introduction: The role of ultrasonography in detection of pleural effusion has long been a subject of interest but 

controversial results have been reported. Accordingly, this study aims to conduct a systematic review of the avail-

able literature on diagnostic value of ultrasonography and radiography in detection of pleural effusion through a 

meta-analytic approach. Methods: An extended search was done in databases of Medline, EMBASE, ISI Web of 

Knowledge, Scopus, Cochrane Library, and ProQuest. Two reviewers independently extracted the data and as-

sessed the quality of the articles. Meta-analysis was performed using a mixed-effects binary regression model. 

Finally, subgroup analysis was carried out in order to find the sources of heterogeneity between the included 

studies. Results: 12 studies were included in this meta-analysis (1554 subjects, 58.6% male). Pooled sensitivity 

of ultrasonography in detection of pleural effusion was 0.94 (95% CI: 0.88-0.97; I2= 84.23, p<0.001) and its 

pooled specificity was calculated to be 0.98 (95% CI: 0.92-1.0; I2= 88.65, p<0.001), while sensitivity and specific-

ity of chest radiography were 0.51 (95% CI: 0.33-0.68; I2= 91.76, p<0.001) and 0.91 (95% CI: 0.68-0.98; I2= 

92.86, p<0.001), respectively. Sensitivity of ultrasonography was found to be higher when the procedure was car-

ried out by an intensivist or a radiologist using 5-10 MHz transducers. Conclusion: Chest ultrasonography, as a 

screening tool, has a higher diagnostic accuracy in identification of plural effusion compared to radiography. The 

sensitivity of this imaging modality was found to be higher when performed by a radiologist or an intensivist and 

using 5-10MHz probes. 

Key words: Pleural Effusion; ultrasonography; radiography; diagnostic tests, routine  
Cite this article as: Yousefifard M, Baikpour M, Ghelichkhani P, et al. Screening performance characteristic of ultrasonography 
and radiography in detection of pleural effusion; a meta-analysis. Emergency. 2016;4(1):1-10. 

Introduction: 
The role of ultrasonography in detection of pleural effu-
sion was first discovered in the 1960s (1). One decade 
later the diagnostic value of A-mode ultrasonography in 
identification of pleural effusion was reported to be 95% 
(2). Thus, the impression that ultrasonography is not a 
suitable modality for detection of chest lesions was re-
jected at that time. Afterwards, various surveys were 
conducted evaluating the diagnostic accuracy of ultraso-
nography and radiography in identification of pleural ef-
fusion and most of them found a higher diagnostic value 

for ultrasonography compared to radiography (3-5). 
However, ultrasonography is still not considered as the 
first diagnostic tool for detection of pleural effusion and 
the majority of physicians use radiography for this pro-
pose (6).   
Although a radiogram captured in lateral decubitus po-
sition with horizontal rays has a high sensitivity and 
specificity in detection of pleural effusion but it cannot 
be obtained from all the patients especially critically ill 
and trauma victims (4). Other views of chest radiogram 



 

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Yousefifard et al 2 

have low sensitivities in this regard (7, 8). Vast improve-
ments of technology have led to development of hand-
held and pocket-size ultrasound devices (9, 10). A meta-
analysis was performed in 2010 on four studies that re-
ported the sensitivity and specificity of ultrasonography 
in detection of pleural effusion to be 93% and 96%, re-
spectively (11). Yet, inclusion of few surveys and lack of 
sensitivity analysis and publication bias confirm the ne-
cessity of an update on this subject. Therefore, this study 
aims to conduct a systematic review of the available lit-
erature determining the diagnostic value of ultrasonog-
raphy and radiography for detection of pleural effusion 
through a meta-analytic approach.  
 
Methods: 
Search strategy and selection criteria 

This study was designed according to the consensus 
statement of Meta-analysis of Observational Studies in 
Epidemiology (MOOSE) (12). Extended systematic 
search was carried out in databases of Medline (via Pub-
Med), EMBASE (via OvidSP), ISI Web of Knowledge, Sco-
pus, Cochrane Library, and ProQuest based on the key-
words obtained from Medical Subject Heading (MeSH) 
terms and EMTREE. The keywords included “Ultraso-
nography” OR “Sonography” OR “Ultrasound” OR “Chest 
Film” OR “Chest Radiograph” combined with “Pleural Ef-
fusion” OR “Effusion” OR “Pleural Free Fluid”. The di-
rective was to find prospective and retrospective studies 
assessing the diagnostic value of ultrasonography or 
chest radiography in detection of pleural effusion. Two 
of the authors (M.Y, P.G) independently searched for 
sources and contacted the authors of relevant articles to  

 

Figure 1: Flowchart of the study. 



  
  

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3 Emergency (2016); 4 (1): 1-10 

 

  
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http://acr.sagepub.com/search?author1=Stephan+Schleder&sortspec=date&submit=Submit
http://tumj.tums.ac.ir/search.php?slc_lang=en&sid=1&auth=Kasraei


 

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Yousefifard et al 4 

obtain further articles and data. Only original articles 
were included. The studies that had used radiography as 
their reference test were excluded and only surveys in 
which a final diagnosis of pleural effusion had been con-
firmed by computed tomography scan or surgery were 
included. The search yielded three surveys which had 
compared the diagnostic value of pocket-size ultraso-
nography machines with high-end ones. Since these 
high-end ultrasonography machine had been performed 
by cardiologists and their results had been assessed by 
the final diagnosis proposed by two specialists as the ref-
erence test, these three surveys were also included in the 
meta-analysis. 
Data extraction 
The articles were entered into Endnote X7 software and 
after elimination of duplicates, two reviewers (M.Y, P.G) 
independently screened the articles. Full texts of the ar-
ticles were studied and summarization was done. Qual-
ity of the surveys were evaluated according to the guide-
lines proposed by 14-Item Quality Assessment of Diag-
nostic Accuracy Studies (QUADAS2) tool (18). Each arti-
cle was assessed regarding presence of various biases in-
cluding selection, performance, recording, and reporting 
and they were classified as three grades of poor, fair or 
good. Only fair and good surveys were included in meta-
analysis. Data on distribution of the study population re-
garding age and gender, sample size, the number of pa-
tients with/without pleural effusion according to refer-
ence tests, technique of ultrasonography, the specialty of 
the ultrasound device’s operator, sonographic definition 
of pleural effusion, probe’s frequency, blinding status, 
sampling method (consecutive, convenience) and finally 
number of true and false, positive and negative cases 
were gathered. A third author (M.H) was in charge of 
solving disagreements. In cases where data were not 
presented in the article web-based programs were used 
to compute true positive, false positive, true negative 
and false negative figures according to sensitivity and 
specificity. When available, data for each hemi-thorax 
were included in the analysis separately. 
Statistical analysis         
STATA 11.0 statistical software was used to analyze the 
data via MIDAS module. To evaluate the adequacy of ul-
trasonography and radiography in detection of pleural 
effusion, summary receiver operative curves (SROC), 
sensitivity, specificity, positive likelihood ratio, and neg-
ative likelihood ratio with 95% confidence interval (95% 
CI) were calculated using a mixed-effects binary regres-
sion model. Heterogeneity between the included surveys 
was assessed through utilization of I2 and χ2 tests and a 
p value of less than 0.1 along with an I2 greater than 50% 
were considered as positive heterogeneity (19). Conse-
quently, subgroup analysis was performed on sampling 
method (consecutive/ convenience), operator (emer-

gency physician/ other specialists) or interpreting phy-
sician, frequency of the probe (1-5 MHz/ 5-10 MHz), type 
of ultrasound device (pocket-size/other) and sample 
size (less than 100 patients/ more than 100 patients). 
 
Results: 
Study characteristics 
Search process and the number of articles obtained in 
each step are presented in Figure 1. Twenty one studies 
met the inclusion criteria. One survey was also found 
through manual search. After detailed evaluation of 
these surveys 12 studies were included in meta-analysis 
(3-5, 7-10, 13-17). The characteristics of included stud-
ies are presented in Table 1. The mean age of the subjects 
was 63.3 years (ranging from 14 to 101 years old) and 
58.6% were male. All the studies were single-center (3-
5, 7-10, 14-17)except one which was performed in two 
center (13). A total of 646 patients with pleural effusion 
and 912 subjects without it were evaluated. Diagnostic 
accuracy of both these modalities was assessed in nine 
surveys (3-5, 8-10, 13-17), radiography was evaluated 
individually in one study (7) and ultrasonography was 
assessed individually in two articles (10, 17). 11 articles 
were in English (3-5, 7-10, 13-15, 17) and one was in 
Farsi (16). The presence of heterogeneity was confirmed 
between the studies (P<0.1), but no publication bias was 
detected (Figure 2). 
Meta-analysis 
Area under the curve of SROCs for ultrasonography and 
chest radiography in detection of pleural effusion were 
0.98 (95% CI: 0.97-0.99) and 0.73 (95% CI: 0.69-0.77), 
respectively (Figure 3). Pooled sensitivity and specificity 
of ultrasonography in detection of pleural effusion were 
0.94 (95% CI: 0.88-0.97; I2= 84.23, p<0.001) and 0.98 
(95% CI: 0.92-1.0; I2= 88.65, p<0.001), respectively. 
Also, its pooled positive and negative likelihood ratios 
were calculated to be 53.96 (95% CI: 11.46-254.05; I2= 
88.12, p<0.001) and 0.06 (95% CI: 0.03-0.12; I2= 84.44, 
p<0.001), respectively (Figure 4). 
Pooled sensitivity and specificity of radiography in pleu-
ral effusion diagnosis were 0.51 (95% CI: 0.33-0.68; I2= 
91.76, p<0.001) and 0.91 (95% CI: 0.68-0.98; I2= 92.86, 
p<0.001), respectively. In addition, its pooled positive 
and negative likelihood ratios were also found to be 5.60 
(95% CI: 1.14-27.42; I2= 88.14, p<0.001) and 0.54 (95% 
CI: 0.35-0.84; I2= 84.44, p<0.001), respectively (Figure 
5).  
Subgroup Analysis 
Subgroups analyses were performed regarding study de-
sign, patients’ type (critically ill / other), operator of ul-
trasound machine, ultrasound model and sample size. 
The results showed that the sensitivity was higher when 
the procedure was performed via an intensivist or a ra-
diologist, using 5-10 MHz transducers, whereas it was 



  
  

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5 Emergency (2016); 4 (1): 1-10 

  

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Yousefifard et al 6 

lower when carried out via pocket-size devices. On the 
other hand, the specificity of this modality was not influ-
enced by any of these factors. 
The diagnostic value of radiography was affected by the 
sample size and type of patients. In this regard, the sen-
sitivity and specificity of chest radiography was found to 
be higher in studies with sample sizes of greater than 
100 patients while both of these measures were calcu-
lated to be lower in critically ill patients (Table 2). 
 
Discussion: 
The present meta-analysis showed that ultrasonography 
has high sensitivity (94%) and specificity (98%) in de-
tection of pleural effusion. When the analysis was limited 
to the surveys in which the procedure was carried out by 
an intensivist or a radiologist, the presented sensitivity 
increased (98%). While, the diagnostic value of radiog-
raphy was reported to be lower than ultrasonography 
(sensitivity 51%, specificity 91%). When we limited the 
analyses to studies in which the etiology of pleural effu-
sion was trauma, surgery or congestive heart failure, 
sensitivity of radiography slightly increased (58%). On 
this basis it can be concluded that ultrasonography is a 
better diagnostic tool for pleural effusion compared to 
radiography. 
In comparison with the results of the present study, 
Grimberg et al. reported similar results in their review of 
four articles. They found the sensitivity and specificity of 
ultrasonography to be 93% and 96% respectively while 
these figures for radiography were calculated to be 24% 
and 100% (11). Our results were almost similar to Grim-
berg’s et al. study. The higher sensitivity of radiography 
presented in this study might be due to inclusion of more 
surveys in the analyses. Grimberg’s survey lacked sub-
group analysis which prevents us from further compari-
sons. In another meta-analysis Chavez et al. reviewed 10 
articles aiming to evaluate the diagnostic value of ultra-
sonography in detection of pneumonia and they found a 
sensitivity of 94% and a specificity of 96% for this mo-
dality (20). These researchers stated that ultrasonogra-
phy is a suitable diagnostic tool for ruling out pneumonia 
in patients referring to medical centers and emergency 
departments. Congruent with this survey we also found 
a considerable diagnostic value for ultrasonography in 
detection of pleural effusion.  
One of the factors that influence sensitivity of ultraso-
nography is the operator of ultrasound device which has 
been verified by various surveys in the past years (21-
24). An ultrasonography carried out by an intensivist or 
a radiologist is able to detect pleural effusion more effec-
tively and precisely.  
Pocket-size ultrasonography is a new technology re-
cently being used in some medical centers and reported 
to be an effective modality in diagnostic procedures (25-
27). This machine transmits high resolution pictures 

that help physicians to make more precise decisions re-
garding the patients’ pathology (28, 29). Accordingly, we 
found three studies which assess the diagnostic accuracy 
of pocket-size ultrasonography for pleural effusion (9, 
10, 17), in two of which the procedure was performed by 
a trained nurse (9, 10) and in one it was carried out by 
an internal medicine specialist (17). The first two re-
ported a sensitivity of approximately 92-98% and the 
latter survey found a sensitivity of 62% in detection of 
pleural effusion. This inconsistency might have been due 
to the different study populations. Graven et al. and Da-
len et al. only included cardiac patients while Stock et al. 
evaluate patients with various diseases. Nevertheless, 
the sample sizes of all the three surveys were small and 
so further investigation is required for application of this 
ultrasonography device in clinical settings.  
In this meta-analysis the extended search in databases 
and bibliographies yielded 12 relevant articles. Although 
few studies were included in this study, but the large 
sample population of 1554 subjects assured the validity 
of performed analyses to a great extent. Presence of no 
publication bias confirms this declaration. Heterogene-
ity between the articles was another limitation of this 
survey which was attempted to overcome through appli-
cation of mixed-effects binary regression model and sub-
group analysis. Simultaneous inclusion of retrospective 
and prospective surveys was probable limitation of this 
study, but the scatterplot developed to evaluate the out-
lier studies according to standardized predicted random 
effects showed that retrospective surveys were not the 
source of diversity between the included articles.   
 
Conclusion: 
The present meta-analysis found chest ultrasonography 
to have a considerably higher screening value in detec-
tion of pleural effusion compare to radiography. Being 
performed by an intensivist or a radiologist and using 
probes with frequencies of 5-10MHz improves the sensi-
tivity of this imaging modality. 
 
Acknowledgments: 
None 
 
Conflict of interest: 
None 
 
Funding support: 
This research has been supported by Tehran University 
of Medical Sciences & health Services grant number: 93-
02-38-25618. 
 
Authors’ contributions: 
All authors passed four criteria for authorship contribu-

tion based on recommendations of the International 

Committee of Medical Journal Editors. 



  
  

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7 Emergency (2016); 4 (1): 1-10 

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Imaging. 2013;14(12):1195-202.

 

 



 

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Yousefifard et al 8 

  

A B 

  
Figure 2: Deeks’ funnel plot asymmetry test for assessment of publication bias. P values < 0.05 were considered as significant. 
Ultrasonography (A); Radiography (B). ESS: Effective sample sizes. 
 
 
 
 

A B 

  
Figure 3: Summary receiver operative curves (SROC) for ultrasound (A) and chest radiography (B) in detection of plural effusion. 
AUC: Area under the curve; SENS: Sensitivity; SPEC: Specificity. 

1

2

3

4

5

6

7

8

9

10

11

12

.05

.1

.15

.2

1
/

ro
o

t(
E

S
S

)

1 10 100 1000

Diagnostic Odds Ratio

Study

Regression
Line

Deeks' Funnel Plot Asymmetry Test
pvalue  =   0.80

 

1

2

3

4

5

6

7

8

9

10

.05

.1

.15

.2

1
/

ro
o

t(
E

S
S

)

1 10 100 1000

Diagnostic Odds Ratio

Study

Regression
Line

Deeks' Funnel Plot Asymmetry Test
pvalue  =   0.76

 

1

2

3
4

5

6

7

8

9
10 11

12

0.0

0.5

1.0

S
e

n
si

ti
v

it
y

0.00.51.0
Specificity

Observed Data

Summary Operating Point
SENS = 0.94 [0.88 - 0.97]
SPEC = 0.98 [0.92 - 1.00]

SROC Curve
AUC = 0.98 [0.97 - 0.99]

95% Confidence Contour

95% Prediction Contour

SROC with Prediction & Confidence Contours

1

2

3

4

5

6

7

8

9

10

0.0

0.5

1.0

S
e

n
si

ti
v

it
y

0.00.51.0
Specificity

Observed Data

Summary Operating Point
SENS = 0.51 [0.33 - 0.68]
SPEC = 0.91 [0.68 - 0.98]

SROC Curve
AUC = 0.73 [0.69 - 0.77]

95% Confidence Contour

95% Prediction Contour

SROC with Prediction & Confidence Contours



  
  

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9 Emergency (2016); 4 (1): 1-10 

  

A 

 
B 

  

 

Figure 4: Forest plot of screening performance characteristics of chest ultrasonography in detection of plural effusion. Sensitivity 
and specificity (A); Diagnostic likelihood ratio (DLR) (B). CI: Confidence interval. 

SENSITIVITY (95% CI)

Q = 69.76, df = 11.00, p =  0.00

I2 = 84.23 [76.34 - 92.13]

 0.94[0.88 - 0.97]

0.62 [0.38 - 0.82]

0.92 [0.79 - 0.98]

0.98 [0.93 - 1.00]

1.00 [0.87 - 1.00]

0.91 [0.77 - 0.98]

1.00 [0.94 - 1.00]

0.84 [0.64 - 0.95]

0.95 [0.82 - 0.99]

0.92 [0.85 - 0.96]

0.90 [0.83 - 0.96]

0.90 [0.79 - 0.96]

0.96 [0.80 - 1.00]0.96 [0.80 - 1.00]

Author / year

COMBINED

 

 

Stock 2015

Dalen 2015

Graven 2015

Kasraei 2014

Schleder 2012

Xirouchaki 2011

Zanobetti 2011

Rocco 2008

Lichtenstein 2004

Rozycki 2001

Kataoka 2000

Ma 1997

0.4 1.0

SPECIFICITY (95% CI)

Q = 96.90, df = 11.00, p =  0.00

I2 = 88.65 [83.46 - 93.83]

 0.98[0.92 - 1.00]

0.89 [0.52 - 1.00]

0.99 [0.94 - 1.00]

0.70 [0.47 - 0.87]

1.00 [0.59 - 1.00]

1.00 [0.75 - 1.00]

1.00 [0.84 - 1.00]

0.73 [0.39 - 0.94]

0.99 [0.96 - 1.00]

0.93 [0.89 - 0.96]

1.00 [0.92 - 1.00]

0.95 [0.77 - 1.00]

1.00 [0.98 - 1.00]1.00 [0.98 - 1.00]

Author / year

COMBINED

 

 

Stock 2015

Dalen 2015

Graven 2015

Kasraei 2014

Schleder 2012

Xirouchaki 2011

Zanobetti 2011

Rocco 2008

Lichtenstein 2004

Rozycki 2001

Kataoka 2000

Ma 1997

0.4 1.0

 

DLR POSITIVE (95% CI)

Q = 88.12, df = 11.00, p =  0.00

I2 = 81.66 [81.66 - 93.37]

 53.96[11.46 - 254.05]

5.57 [0.85 - 36.44]

78.46 [11.16 - 551.76]

3.22 [1.73 - 5.97]

15.71 [1.07 - 230.17]

25.28 [1.66 - 385.25]

43.66 [2.82 - 676.25]

3.08 [1.16 - 8.21]

134.53 [19.05 - 949.80]

13.06 [8.53 - 20.01]

84.60 [5.37 - 1000]

19.80 [2.91 - 134.62]

406.11 [25.45 - 1000]406.11 [25.45 - 1000]

Author / year

COMBINED

 

 

Stock 2015

Dalen 2015

Graven 2015

Kasraei 2014

Schleder 2012

Xirouchaki 2011

Zanobetti 2011

Rocco 2008

Lichtenstein 2004

Rozycki 2001

Kataoka 2000

Ma 1997

0.9 1000.0

DLR NEGATIVE (95% CI)

Q = 70.67, df = 11.00, p =  0.00

I2 = 84.44 [76.67 - 92.20]

 0.06[0.03 - 0.12]

0.43 [0.24 - 0.77]

0.08 [0.03 - 0.23]

0.03 [0.01 - 0.12]

0.02 [0.01 - 0.30]

0.10 [0.04 - 0.27]

0.01 [0.01 - 0.13]

0.22 [0.08 - 0.58]

0.05 [0.01 - 0.20]

0.09 [0.04 - 0.17]

0.10 [0.06 - 0.18]

0.10 [0.05 - 0.23]

0.06 [0.01 - 0.26]0.06 [0.01 - 0.26]

Author / year

COMBINED

 

 

Stock 2015

Dalen 2015

Graven 2015

Kasraei 2014

Schleder 2012

Xirouchaki 2011

Zanobetti 2011

Rocco 2008

Lichtenstein 2004

Rozycki 2001

Kataoka 2000

Ma 1997

0 1

 



 

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3.0). Copyright © 2016 Shahid Beheshti University of Medical Sciences. All rights reserved. Downloaded from: www.jemerg.com 

 

Yousefifard et al 10 

 

A 

 
B 

  

 

Figure 5: Forest plot of screening performance characteristics of chest radiography in detection of plural effusion. Sensitivity and 
specificity (A); Diagnostic likelihood ratio (DLR) (B). CI: Confidence interval. 

SENSITIVITY (95% CI)

Q =106.76, df = 9.00, p =  0.00

I2 = 91.57 [87.67 - 95.47]

 0.51[0.33 - 0.68]

0.40 [0.30 - 0.51]

0.33 [0.17 - 0.54]

0.74 [0.57 - 0.88]

0.65 [0.52 - 0.77]

0.16 [0.05 - 0.36]

0.66 [0.61 - 0.70]

0.24 [0.11 - 0.40]

0.39 [0.29 - 0.49]

0.43 [0.31 - 0.57]

0.96 [0.80 - 1.00]0.96 [0.80 - 1.00]

Author / year

COMBINED

 

 

Graven 2015

Kasraei 2014

Schleder 2012

Xirouchaki 2011

Zanobetti 2011

Kitazono 2010

Rocco 2008

Lichtenstein 2004

Kataoka 2000

Ma 1997

0.0 1.0

SPECIFICITY (95% CI)

Q =126.09, df = 9.00, p =  0.00

I2 = 92.86 [89.72 - 96.00]

 0.91[0.68 - 0.98]

0.78 [0.56 - 0.93]

1.00 [0.59 - 1.00]

0.31 [0.09 - 0.61]

0.81 [0.58 - 0.95]

0.27 [0.06 - 0.61]

0.89 [0.85 - 0.92]

0.96 [0.91 - 0.98]

0.85 [0.81 - 0.89]

1.00 [0.85 - 1.00]

1.00 [0.98 - 1.00]1.00 [0.98 - 1.00]

Author / year

COMBINED

 

 

Graven 2015

Kasraei 2014

Schleder 2012

Xirouchaki 2011

Zanobetti 2011

Kitazono 2010

Rocco 2008

Lichtenstein 2004

Kataoka 2000

Ma 1997

0.1 1.0

 

DLR POSITIVE (95% CI)

Q =110.63, df = 9.00, p =  0.00

I2 = 88.14 [88.14 - 95.59]

 5.60[1.14 - 27.42]

1.84 [0.82 - 4.15]

5.43 [0.35 - 83.50]

1.07 [0.71 - 1.62]

3.42 [1.39 - 8.40]

0.22 [0.08 - 0.58]

5.96 [4.35 - 8.17]

5.61 [2.13 - 14.77]

2.64 [1.82 - 3.82]

19.98 [1.27 - 314.61]

406.11 [25.45 - 1000]406.11 [25.45 - 1000]

Author / year

COMBINED

 

 

Graven 2015

Kasraei 2014

Schleder 2012

Xirouchaki 2011

Zanobetti 2011

Kitazono 2010

Rocco 2008

Lichtenstein 2004

Kataoka 2000

Ma 1997

0.1 1000.0

DLR NEGATIVE (95% CI)

Q = 87.40, df = 9.00, p =  0.00

I2 = 89.70 [84.66 - 94.75]

 0.54[0.35 - 0.84]

0.77 [0.58 - 1.00]

0.70 [0.51 - 0.97]

0.84 [0.31 - 1.00]

0.43 [0.29 - 0.64]

3.08 [1.16 - 1.00]

0.39 [0.34 - 0.44]

0.80 [0.67 - 0.95]

0.72 [0.61 - 0.84]

0.58 [0.46 - 0.73]

0.06 [0.01 - 0.26]0.06 [0.01 - 0.26]

Author / year

COMBINED

 

 

Graven 2015

Kasraei 2014

Schleder 2012

Xirouchaki 2011

Zanobetti 2011

Kitazono 2010

Rocco 2008

Lichtenstein 2004

Kataoka 2000

Ma 1997

0 3