| Standardized mean grade difference (regression coefficient (95% CI)) a | ||||
---|---|---|---|---|---|
 | Mathematics 1 | Mathematics 2 | Danish 1 | Danish 2 | Danish 3 |
 | Solving abilities | Mathematical skills | Oral | Reading comprehension | Spelling |
Preterm birth | |||||
 ≥ 37 | REF | REF | REF | REF | REF |
 < 37 |  − 0.054 (− 0.066 to − 0.042) |  − 0.077 (− 0.089 to − 0.065) |  − 0.020 (− 0.032 to − 0.008) |  − 0.066 (− 0.078 to − 0.054) |  − 0.036 (− 0.048 to − 0.024) |
Gestational weeks | |||||
Difference b | 0.009 (0.007 to 0.011) | 0.013 (0.011 to 0.014) | 0.004 (0.002 to 0.005) | 0.010 (0.008 to 0.011) | 0.006 (0.004 to 0.007) |
 ≥ 40 weeks | REF | REF | REF | REF | REF |
 ≤ 33 |  − 0.141 (− 0.166 to − 0.117) |  − 0.179 (− 0.203 to − 0.155) |  − 0.037 (− 0.061 to − 0.012) |  − 0.118 (− 0.142 to − 0.094) |  − 0.051 (− 0.074 to − 0.027) |
 34 ~ 35 |  − 0.039 (− 0.060 to − 0.019) |  − 0.067 (− 0.088 to − 0.047) |  − 0.019 (− 0.040 to 0.001) |  − 0.070 (− 0.090 to − 0.050) |  − 0.037 (− 0.058 to − 0.017) |
 36 |  − 0.025 (− 0.044 to − 0.007) |  − 0.040 (− 0.059 to − 0.021) |  − 0.015 (− 0.034 to 0.003) |  − 0.043 (− 0.062 to − 0.025) |  − 0.033 (− 0.052 to − 0.015) |
 37 ~ 39 |  − 0.012 (− 0.017 to − 0.006) |  − 0.017 (− 0.022 to − 0.012) |  − 0.005 (− 0.011 to − 0.000) |  − 0.011 (− 0.016 to − 0.006) |  − 0.008 (− 0.013 to − 0.003) |
p for trend |  < 0.001 |  < 0.001 | 0.003 |  < 0.001 |  < 0.001 |