Figure 1

Percentage of women that receive periodic mammograms by age and cohort of birth. Catalonia (Spain). The marks indicate the observed percentages at the Catalan health surveys in 1994, 2002, and 2006. The lines are the estimated percentages obtained using the mixed effects model $p=\frac{{\varphi }_1}{1+exp[({\varphi }_2-age)/{\varphi }_3]}$ with parameters ϕ ₁ and ϕ ₃ fixed and parameter ϕ ₂ random.