Fig. 2

Detail of the intake frequency and the intake amount modeling in the SPADE 2-part model. Legend: Firstly, the SPADE 2-part model estimate the intake frequency and then it estimates the intake amounts. Finally, the intake frequency and the intake amount are combined to obtain the usual intake distribution of (a) whole the population when information on the never-consumers is not taken into account; or (b) the consumers only when information on the never-consumers is taken into account [21, 22]