Details of the mixed-effect model (model 1)
| Covariates | Variance | SD | ICC | MOR |
| A.DHB only | 0.046 | 0.216 | 0.014 | 1.23 |
| B.Adjusted (individual level variables)—age, sex, ethnicity | 0.026 | 0.161 | 0.008 | 1.17 |
| C.Adjusted (individual and area level variables)—age, sex, ethnicity, deprivation and rurality | 0.02 | 0.141 | 0.006 | 1.14 |
| D.Adjusted (individual, area and DHB level variables)—age, sex, ethnicity, deprivation, rurality and finance | 0.018 | 0.135 | 0.005 | 1.14 |
| E.Adjusted (individual, area and DHB level variables)—age, sex, ethnicity, deprivation, rurality, finance and year | 0.018 | 0.135 | 0.005 | 1.14 |
DHB, District Health Board; ICC, intracluster correlation coefficient; MOR, median OR.