Table 2.
Model 1: predictors of numbers of patients on practice hypertension registers adjusted for practice size, n = 8052 in final modela
| Predictor | Beta (95% CI) | IRRb (95% CI) | Effect size | P-value |
|---|---|---|---|---|
| IMD | 0.001 (0.0004 to 0.002) | 1.001 (1.0003 to 1.002) | 0.1% | 0.001 |
| Proportion aged ≥65 years | 0.04 (0.038 to 0.041) | 1.04 (1.03 to 1.05) | 4% | <0.001 |
| Proportion of white ethnicity | 0.000007 (0.000005 to 0.00001) | 1.000007 (1.000004 to 1.00001) | 0.0007% | <0.001 |
| Proportion reporting poor health | 0.013 (0.01 to 0.02) | 1.013 (1.01 to 1.02) | 1.3% | <0.001 |
| Practice list size | −0.000008 (−0.000009 to −0.000007) | 0.999992 (0.999991 to 0.999994) | −0.0008% | <0.001 |
| GPs per 1000 practice population | 0.06 (0.03 to 0.09) | 1.06 (1.03 to 1.1) | 6% | <0.001 |
| Total Quality and Outcomes Framework points for hypertension management | 0.006 (0.004 to 0.008) | 1.006 (1.004. 1.008) | 0.6% | <0.001 |
IMD = Index of Multiple Deprivation. IRR = incident rate ratio.
a
Statistical model: negative binomial regression, using log of the list size as the offset.
b
Subtracting 1 from the IRR and then multiplying by 100 gives the percentage change in the expected count for a one-unit increase in the predictor. So for practice deprivation score, for every extra deprivation point, the expected count increases by 0.1%. IRR values less than 1.0 represent decreases and IRR values greater than 1.0 represent increases in the count.