Table 2

Factors associated with serum retinol changes in Kaya pupils (ANCOVA with repeated measures)

Within subject effects

Source

Sum of squares

df

F

P value

Time factor

0.89

1

6.30

0.013

Time factor* age

1.60

1

11.58

0.001

Time factor* height-for-age Z-score

0.88

1

6.39

0.012

Time factor* sex

0.56

1

4.08

0.045

Error

28.74

210

-

-

Zeba et al. Nutrition Journal 2006 5:17   doi:10.1186/1475-2891-5-17