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Table 5 Scores for assessment of quality for case control studies using the Newcastle Ottawa Scale

From: The potential role of the antioxidant and detoxification properties of glutathione in autism spectrum disorders: a systematic review and meta-analysis

 

Jory & McGinnis 2008

Rose et al. 2008

Vojdani et al. 2008

James et al. 2009

James et al. 2009 (in vitro)

Al-Gadani et al. 2009

Pasca et al. 2009

Pastural et al. 2009

Geier & Geier 2009

Adams et al. 2009

Mostafa et al. 2010

Vergani et al. 2011

Al-Yafee et al. 2011

Adams et al. 2011

Tirouvanzium et al. 2011

Max score

1 Selection

                

   Case definition

1

1

1

1

2

2

2

1

2

1

2

1

2

1

1

2

   Representativeness

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

   Selection of controls

0

0

1

0

0

0

0

0

0

0

1

0

1

0

0

2

   Definition of controls

0

0

0

1

1

0

1

0

0

0

1

1

1

2

1

2

2 Comparability

                

   Control for confounding

0

0

0

1

1

1

2

0

0

0

2

0

0

0

2

2

3 Exposure

                

   Ascertainment

0

0

0

0

0

0

0

0

0

1

0

0

0

1

0

1

   Method same for cases/controls

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

   Overall score

2

2

3

4

5

4

6

2

3

3

7

3

5

5

5

9