Bland-Altman plot of total intake of herbs and spices. Bland-Altman plot of the difference between herb and spice intake from the FFQ and the HSR, against the mean of the FFQ and HSR intakes, for each participant. The solid line represents the average difference between the intakes from the FFQ and the HSR (2.5 g/d for the whole study population, 1.7 g/d without 4 extreme outliers). The dotted lines are upper and lower limits of agreement (mean ± 1.96 SD) in this population. 4 extreme outliers of intake from the FFQ are excluded form the plot but not from the calculations.
Carlsen et al. Nutrition Journal 2011 10:50 doi:10.1186/1475-2891-10-50