Multiple regression analysis of the factors associated with the incidence of Perthes' disease in the period 1990–95
| B | t | p value | |
| Change in z score for deprivation between 1976 and 1995 | 2.670 | 3.196 | 0.003 |
| Percent low birth weight in 1981 | 3.361 | 2.706 | 0.011 |
| Percent free school meals in 1986 | −0.233 | −2.356 | −0.026 |
| Health index in 1981 (z score) | −2.425 | −2.016 | 0.054 |
R2 44%; df (4, 28); F ratio = 5.53; p value = 0.002.
Data for ward deprivation rates were only available for Liverpool City. The table is based on 33 wards, not 78. B is the regression coefficient. The table indicates that the incidence of LCPD changes 2.67 units per unit change in z score. R2 represents the percentage variation explained by the variables in the model.