Model | −2 log likelihood | Likelihood ratio* | Degrees of freedom | p value |
---|---|---|---|---|
*Likelihood ratio statistic (χ2) comparing the nested models. | ||||
†Compared to the intercept only model. | ||||
‡Compared to the linear model. | ||||
§Compared to the quadratic model. | ||||
¶Compared to the quadratic spline restricted both tails. | ||||
Lifting and carrying loads over 10 kg (work hours per week) | ||||
Intercept only | 721.5 | |||
Linear | 711.1 | 10.4† | 1 | 0.02 |
Quadratic | 707.0 | 4.1‡ | 1 | 0.04 |
Quadratic spline restricted both tails | 703.3 | 3.7§ | 1 | 0.05 |
Quadratic spline | 700.5 | 2.8¶ | 2 | 0.25 |