Table 3.
Genetic modelling analysis for low back pain (LBP)
| Model | χ2 | df | AIC | χ2 | df | P-value | |
|---|---|---|---|---|---|---|---|
| I | ACEm, ACEf, sex diff | 39.98 | 31 | −22.02 | – | – | – |
| II | ACEm, ACEf, no sex diff | 39.98 | 32 | −24.02 | 0.00 | 2 | 1.00 |
| III | ACE equal in boys and girls | 42.91 | 34 | −25.09 | 2.93 | 3 | 0.40 |
| IV | AEa | 49.53 | 35 | −20.47 | 6.61 | 1 | 0.01 |
| V | CEa | 44.52 | 33 | −25.48 | 1.57 | 1 | 0.21 |
| VI | Ea | 152.88 | 36 | 80.88 | 89.97 | 2 | <0.001 |
Prevalences were allowed to be different in boys and girls
Model (I) specifies A, C and E effects in boys that are allowed to differ in size from the A, C and E effects in girls, with sex-specific genetic effects
Model (II) is Model I without any sex-specific genetic effects
Model (III) specified A, C, and E effects of equal size for girls and boys,
Models IV, V and VI are compared to model III: ACE model equal in boys and girls
Best fitting model in bold—fewest components without causing significant deterioration in χ2 goodness-of-fit statistic
A additive genetic, C common environmental, E unique environmental, AIC akaike information criterion = χ2 × df
aCompared to ACE model equal in boys and girls