Table 5.

Two-piecewise regression analysis of the effect of dietary fibre intake on the progression of attachment loss in males and females

Attachment loss progression	Males β (95% CI), P value	Females β (95% CI), P value
Fitting by the standard linear model	-0.0012 (-0.0018, -0.0007) < 0.0001	-0.0008 (-0.0014, -0.0002) 0.0086
Fitting by the two-piecewise linear model
Inflection point	967.5 mg	18.05 mg
Dietary fibre < Inflection point	-0.0018 (-0.0024, -0.0011) < 0.0001	-0.1180 (-0.1743, -0.0618) < 0.0001
Dietary fibre > Inflection point	0.0022 (-0.0003, 0.0047) 0.0863	-0.0002 (-0.0008, 0.0005) 0.6687
Log likelihood ratio	0.006	< 0.001