Table 3a. 3-level regression model—random intercepts of the null model and predictor model.

Variable	Covariance parameter estimate	Standard error
Random intercepts of the null model
Hospital	0.38	0.11
Region (post code 2 digits)	0	–
Random intercepts of the predictor model
Hospital	0.25	0.11
Region (post code 2 digits)	0	0