Figure 6
Interrupted Time Series (ITS) charts for the saba measure generated using the national median, and the median of LSOAs in the most and least deprived deciles. Solid black lines show the observed data. Dashed white lines show a modelled counterfactual which represents expected trends given the pre-intervention period and a controlling covariate. The grey ribbon represents a 95% Bayesian credible interval. Plots show the original data, and pointwise and cumulative subtractions between the observed and counterfactual data. Summary statistics for ITS analysis imply a difference between pre- and post- period for the national median and the median of LSOAs in the least deprived decile, but not for the most deprived (Bayesian one-sided tail-area probability p = 0.001). LSOA lower layer super output area, SABA short-acting beta agonist.
