Figure 2

Posterior mean value for the temporal and spatial effects for the risk of Kawasaki disease (KD) in Canada from April 2004 to March 2017 based on the Bayesian hierarchical model. Standardized incidence rate above 1 indicate increased risks, and below 1 decreased risks. (a) Monthly temporal unstructured and structured trends. An increasing trend is visible for the unstructured effect (solid line) across time. The structured effect (dashed line) shows nearly no fluctuation. (b) The seasonal effect illustrates a below average standardized incidence rate for KD in September and a high risk in the winter months. (c) Mean spatially autocorrelated random effect, expressed as area-specific standardized incidence rate. Areas with standardized incidence rate larger than 1 have an above average risk compared to the rest of Canada, while standardized incidence rate smaller than 1 indicate a below average risk. The red colours in the Greater Toronto Area and around Halifax for example indicate a 50 to 90% increase of risk. For better visibility of small regions, an interactive map can be found in the online appendix. The spatial units (of the analysis regions consisting of several forward sorting areas) are indicated with boundaries and grey filling. White regions were added to the plot for easier orientation. For uncertainty estimates, see online appendix.