Table 1 Discriminant models data.

From: Discriminant analysis and binary logistic regression enable more accurate prediction of autism spectrum disorder than principal component analysis

(a) Data suitability for discriminant analysis

Pooled within-groups matrices (correlation between predictor variables)

Box’s M test p value (cutoff > 0.001)

 

K+

Na+

LDH

MRC1

GST

K+

1

−0.065

−0.215

−0.016

0.12

0.015

Na+

−0.065

1

0.136

−0.038

−0.03

LDH

−0.215

0.136

1

−0.129

−0.103

MRC1

−0.016

−0.038

−0.129

1

0.049

GST

0.12

−0.03

−0.103

0.049

1

(b) Model fitness

Wilk’s Lambda

p value

     

0.525/0.545

2.66 × 10–9/2.24 × 10–9

     

(c) Variable contribution to the discriminant model and inter-group difference of means

 

SCDFC

Wilks’ Lambda (equal for both models)

F test p value (cutoff < 0.01) (equal for both models)

   

K+

−0.626/0.661

0.732 (26.8%)

8.66 × 10–7

   

GST

0.529/−0.547

0.876 (12.4%)

0.0013

   

MRC1

−0.392/0.414

0.871 (12.9%)

0.0011

   

LDH

0.294/−0.341

0.839 (16.1%)

0.0002

   

Na+ (excluded stepwise)

0.276/NC

0.898 (10.2%)

0.0038

   

(d) Discriminant function discriminatory power

 

Eigenvalue

Canonical correlation

    

First discriminant function

0.904/0.837

0.689/0.675

    
  1. (a) Test results aiming to evaluate data suitability for discriminant analysis. (b) Model significance and fitness indicators. (c) Indicators of importance of individual variables to the model. SCDFC indicates the contributions made by each variable to the model, Wilks’ Lambda indicates the amount of variance that is unrelated to group membership with the percentage of relevant variance in parentheses, and the F test p value indicates the significance of differences between group means for each variable. (d) Canonical discriminant function ability to discriminate between groups. The higher the eigenvalue and canonical correlation, the better the model’s ability to discriminate between groups. Results of the all-inclusive and stepwise models are shown separated by a forward slash in (b), SCDFC column in (c), and (d).
  2. SCDFC standardized canonical discriminant function coefficient, NC not calculated.