# Table 1 Probability estimates for linkage analyses

Matching variable Baseline best guesses Dattani et al. [15] estimate
m u $$w_{\mathrm {m}}^{\mathrm {a}}$$ $$w_{\text {nm}}^{\mathrm {b}}$$ m u $$w_{\mathrm {m}}^{\mathrm {a}}$$ $$w_{\text {nm}}^{\mathrm {b}}$$
Date of birth 0.90 0.00274 5.794 -2.3 0.7405 0.0015 6.202 -1.347
GA at birth 0.80 0.02 3.689 -1.589 0.4941 0.0494 2.3028 -0.6308
Sex 0.999 0.49 0.7123 -6.2344 0.7208 0.0062 4.756 -1.270
Discharge date 0.20 0.002 4.6052 -0.2211
Date of death c 0.20 0.00274 4.2904 -0.2204 0.30 0.002 5.0106 -0.3547
Birth weight 0.60 0.001 6.3969 -0.9153 0.7405 0.0074 4.606 -1.342
Birth order 0.87 0.95 -0.08797 0.95551 0.8153 0.0033 5.510 -1.686
Delivery method c 0.80 0.80 0 0 0.67 0.1 1.902 -1.003
Ethnic category 0.20 0.10 0.6931 -0.1178 0.7308 0.095 2.040 -1.212
Mother’s age at delivery 0.95 0.05 2.944 -2.944
Mother’s date of birth 0.90 0.0001 9.105 -2.302
Postcode 0.90 0.001 6.802 -2.302 0.9291 0.065 2.660 -2.579
Number of previous pregnancies 0.60 0.90 -0.4055 1.3863
Number of babies 0.95 0.95 0 0 0.8153 0.0033 5.510 -1.686
1. Probability estimates for linkage analyses between Hospital Episode Statistics and EPICure data based on best guesses and prior knowledge (adapted from data linkage performed by Dattani et al between Hospital Episode Statistics (HES) and NHS Numbers 4 Babies data sets) [15]
2. a w m= weight if pairs match
3. b w nm= weight if pairs do not match
4. cDate of death and delivery method were both modified using an adjusted best guess for the second linkage analysis performed using estimates from Dattani et al.