Fig. 2

Participation rates and random effects in the final spatio-temporal regression model. Spatial pattern of the biennial participation rates, for the periods: 2007–08 (a), 2009–10 (b), and 2011–12 (c). Black dots mark the location of the screening units in the study region. Odds ratios compared to the intercept (α) of the unstructured (Φ_t) and structured (γ_t) temporal effect (d), combined unstructured and structured spatial heterogeneity (u_i + v_i) (e), and spatio-temporal interaction effect (ψ_it) for 2007–08 (f), 2009–10 (g), and 2011–12 (h). All random effects were classified according to their quantiles