Table 4.

Difference in constant systematic error in reporting of fruit and vegetable intake between baseline and each follow-up visit

Visit timeline	Intervention		Control
	βa	p	βa	p
Baseline, 6 months follow-up	0.03	0.73	−0.02	0.83
Baseline, 12 months follow-up	−0.03	0.68	0.04	0.65
Baseline, 18 months follow-up	−0.06	0.50	−0.001	0.99

^aEstimated by regressing visit timeline and fruit and vegetable intake on serum carotenoids, where the slope of visit timeline indicates difference in constant systematic error between baseline and follow-up visit