Table 2.
The coefficient of determination (R2) and p-valuea
| Data set | Response variable | R2 | p-valued |
|---|---|---|---|
| Full range of AFB (N=10836) |
Model1b | 1.1E-03 | 4.1E-04 |
| Model2c | 6.4e-04 | 5.0E-03 | |
| AFB < 26 (N=5827) |
Model1 | 1.8E-03 | 6.2E-04 |
| Model2 | 1.9E-03 | 5.1E-04 | |
| AFB >= 26 (N=5009) |
Model1 | 1.0E-03 | 1.4E-02 |
| Model2 | 6.5E-05 | 2.5E-01 |
Abbreviation: GBLUP, genomic best linear unbiased linear prediction. AFB age at birth in women.
In the analyses, either the Model1 or Model2 variables was used as the dependent variables in regression on GBLUP risk profile score using only women aged 45 years or over at recruitment. AFB was used as the x variable in this study. The analysed Model1 and Model2 variables were the residuals from a regression fitting potential confounders as covariates.
Model1: Polynomial function derived from incidence ratio for schizophrenia by maternal age (x) presented in McGrath et al (2014) (Model1 = 2.7214 + 0.0018x2 – 0.1105x).
Model2: polynomial function derived from incidence ratio for schizophrenia by maternal age adjusted for age of other parent and urbanization of place of birth (x) presented in McGrath et al (2014) (Model2 = 2.5438 + 0.0012x2 + 0.0889x).
Including genetic profile score for educational attainment as a covariate had little impact on these results (eTable 8).
P-value for H0: R2 = 0