Table 4

χ2, df and p for models 0 to 4. Differences between these models are used to test hypotheses of main effects and interactions)

Model
χ2 (df)
p

1 (b = d, a = c = 0)
358.25 (3)
<0.0001
2 (a = c = 0)
357.52 (2)
<0.0001
3 (a = c)
1.764 (1)
0.184
0 (no restrictions)
0 (0)
1.00

Miles BMC Medical Research Methodology 2003 3:27   doi:10.1186/1471-2288-3-27