Appendix 18Comparison of clinical characteristic and biochemical marker models in data imputed with original biochemical markers or natural log-transformed biochemical markers
TABLE 41
First-trimester models for any pre-eclampsia
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Variable | Original biochemical markers | Ln(biochemical markers) |
---|
Beta coefficient (95% CI) | OR (95% CI) | p-value | Beta coefficient (95% CI) | OR (95% CI) | p-value |
---|
Age (years) | –0.023 (–0.038 to –0.008) | 0.977 (0.962 to 0.992) | 0.003 | –0.023 (–0.039 to –0.007) | 0.977 (0.962 to 0.993) | 0.006 |
SBP | 0.016 (0.004 to 0.028) | 1.016 (1.004 to 1.028) | 0.011 | 0.024 (0.014 to 0.034) | 1.024 (1.014 to 1.034) | < 0.001 |
BMI | 0.041 (0.009 to 0.074) | 1.042 (1.009 to 1.077) | 0.015 | 0.036 (0.016 to 0.056) | 1.037 (1.016 to 1.057) | < 0.001 |
Nulliparous | 1.136 (0.597 to 1.675) | 3.113 (1.816 to 5.337) | < 0.001 | 1.267 (0.703 to 1.831) | 3.551 (2.020 to 6.241) | < 0.001 |
Previous PE | 1.350 (0.812 to 1.888) | 3.857 (2.252 to 6.607) | < 0.001 | 1.488 (0.901 to 2.076) | 4.430 (2.461 to 7.973) | < 0.001 |
Renal disease | 0.957 (0.319 to 1.594) | 2.603 (1.376 to 4.925) | 0.004 | 1.058 (0.449 to 1.667) | 2.880 (1.566 to 5.296) | 0.001 |
Hypertension | 2.241 (1.962 to 2.520) | 9.403 (7.113 to 12.430) | < 0.001 | 2.215 (1.949 to 2.482) | 9.165 (7.024 to 11.960) | < 0.001 |
Diabetes | 0.021 (–0.915 to 0.957) | 1.021 (0.401 to 2.605) | 0.965 | 0.178 (–0.737 to 1.094) | 1.195 (0.479 to 2.985) | 0.702 |
sFlt-1 | –2.42 × 10–4 (–4.3 × 10–4 to –5.5 × 10–5) | 0.9998 (0.9996 to 0.9999) | 0.012 | –0.052 (–0.109 to 0.005) | 0.949 (0.897 to 1.005) | 0.071 |
PlGF | –0.005 (–0.008 to –0.002) | 0.995 (0.992 to 0.998) | 0.001 | –0.030 (–0.062 to 0.002) | 0.970 (0.940 to 1.002) | 0.064 |
Intercept | –5.893 (–7.478 to –4.309) | | | –7.022 (–8.515 to –5.530) | | |
TABLE 42
Performance statistics for first-trimester models for any pre-eclampsia
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Model | C-statistic | Calibration slope | Calibration-in-the-large |
---|
Estimate (95% CI) | τ2 (for logit C-statistic) | I2 (for logit C-statistic) | Estimate (95% CI) | τ2 | I2 | Estimate (95% CI) | τ2 | I2 |
---|
Original biochemical markers | 0.696 (0.516 to 0.832) | 0.205 | 90.7 | 0.901 (0.355 to 1.447) | 0.094 | 86.7 | –0.004 (–0.939 to 0.931) | 0.333 | 97.9 |
Ln(biochemical markers) | 0.693 (0.538 to 0.814) | 0.150 | 88.8 | 0.896 (0.302 to 1.491) | 0.120 | 90.5 | 0.008 (–0.874 to 0.889) | 0.291 | 97.1 |
TABLE 43
First-trimester models for early pre-eclampsia
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Variable | Original biochemical markers | Ln(biochemical markers) |
---|
Beta coefficient (95% CI) | OR (95% CI) | p-value | Beta coefficient (95% CI) | OR (95% CI) | p-value |
---|
Age (years) | –0.005 (–0.047 to 0.038) | 0.995 (0.954 to 1.039) | 0.831 | –0.013 (–0.054 to 0.028) | 0.987 (0.947 to 1.028) | 0.523 |
SBP | 0.053 (0.025 to 0.082) | 1.055 (1.026 to 1.085) | < 0.001 | 0.024 (–0.007 to 0.054) | 1.024 (0.993 to 1.055) | 0.125 |
DBP | –0.004 (–0.04 to 0.033) | 0.996 (0.960 to 1.033) | 0.836 | 0.042 (0.004 to 0.080) | 1.043 (1.004 to 1.083) | 0.031 |
BMI | –0.007 (–0.069 to 0.056) | 0.993 (0.933 to 1.057) | 0.831 | 0.006 (–0.049 to 0.061) | 1.006 (0.952 to 1.062) | 0.837 |
Previous PE | 1.488 (0.694 to 2.281) | 4.427 (2.002 to 9.789) | < 0.001 | 1.689 (0.909 to 2.469) | 5.412 (2.481 to 11.805) | < 0.001 |
Renal disease | 1.481 (0.401 to 2.560) | 4.397 (1.494 to 12.942) | 0.007 | 1.414 (0.325 to 2.503) | 4.112 (1.384 to 12.216) | 0.011 |
Hypertension | 0.833 (0.033 to 1.633) | 2.300 (1.034 to 5.117) | 0.041 | 0.978 (0.201 to 1.755) | 2.659 (1.222 to 5.786) | 0.014 |
sFlt-1 | –5.15 × 10–4 (–1.1 × 10–3 to 6.1 × 10–5) | 0.9995 (0.9989 to 1.0001) | 0.079 | | | |
Intercept | –10.206 (–13.561 to –6.851) | | | –10.929 (–13.875 to –7.983) | | |
TABLE 44
Performance statistics for first-trimester models for early pre-eclampsia
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Model | C-statistic | Calibration slope | Calibration-in-the-large |
---|
Estimate (95% CI) | τ2 (for logit C-statistic) | I2 (for logit C-statistic) | Estimate (95% CI) | τ2 | I2 | Estimate (95% CI) | τ2 | I2 |
---|
Original biochemical markers | 0.762 (0.576 to 0.883) | 0.107 | 37.0 | 1.038 (0.666 to 1.410) | 0 | 0 | 0.036 (–1.269 to 1.342) | 0.610 | 91.7 |
Ln(biochemical markers) | 0.745 (0.591 to 0.855) | 0.053 | 27.2 | 1.022 (0.695 to 1.350) | 0 | 0 | 0.014 (–1.240 to 1.268) | 0.552 | 90.2 |
TABLE 45
First-trimester models for late pre-eclampsia
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Variable | Original biochemical markers | Ln(biochemical markers) |
---|
Beta coefficient (95% CI) | OR (95% CI) | p-value | Beta coefficient (95% CI) | OR (95% CI) | p-value |
---|
Age (years) | –0.025 (–0.040 to –0.009) | 0.976 (0.961 to 0.991) | 0.002 | –0.024 (–0.042 to –0.006) | 0.976 (0.959 to 0.994) | 0.009 |
SBP | 0.009 (–0.002 to 0.020) | 1.009 (0.998 to 1.020) | 0.113 | 0.020 (0.010 to 0.030) | 1.020 (1.010 to 1.031) | < 0.001 |
BMI | 0.051 (0.024 to 0.077) | 1.052 (1.024 to 1.080) | < 0.001 | 0.040 (0.018 to 0.061) | 1.040 (1.019 to 1.063) | < 0.001 |
Nulliparous | 1.409 (0.814 to 2.004) | 4.093 (2.258 to 7.418) | < 0.001 | 1.683 (1.035 to 2.330) | 5.379 (2.816 to 10.276) | < 0.001 |
Previous PE | 1.197 (0.557 to 1.838) | 3.311 (1.745 to 6.283) | < 0.001 | 1.456 (0.774 to 2.138) | 4.289 (2.168 to 8.486) | < 0.001 |
Renal disease | 0.758 (0.084 to 1.433) | 2.135 (1.088 to 4.190) | 0.028 | 0.886 (0.225 to 1.547) | 2.426 (1.253 to 4.698) | 0.009 |
Hypertension | 2.374 (2.084 to 2.663) | 10.739 (8.039 to 14.346) | < 0.001 | 2.326 (2.049 to 2.604) | 10.238 (7.756 to 13.515) | < 0.001 |
sFlt-1 | –2 × 10–4 (–3.8 × 10–4 to –2.4 × 10–5) | 0.9998 (0.9996 to 1.0000) | 0.026 | –0.06 (–0.119 to –0.001) | 0.942 (0.888 to 0.999) | 0.048 |
PlGF | –0.006 (–0.009 to –0.003) | 0.994 (0.991 to 0.997) | 0.001 | –0.032 (–0.066 to 0.003) | 0.969 (0.936 to 1.003) | 0.072 |
Intercept | –5.787 (–7.28 to –4.293) | | | –7.168 (–8.776 to –5.559) | | |
TABLE 46
Performance statistics for first-trimester models for late pre-eclampsia
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Model | C-statistic | Calibration slope | Calibration-in-the-large |
---|
Estimate (95% CI) | τ2 (for logit C-statistic) | I2 (for logit C-statistic) | Estimate (95% CI) | τ2 | I2 | Estimate (95% CI) | τ2 | I2 |
---|
Original biochemical markers | 0.688 (0.505 to 0.827) | 0.212 | 91.9 | 0.857 (0.338 to 1.376) | 0.085 | 84.4 | –0.005 (–0.932 to 0.922) | 0.322 | 97.5 |
Ln(biochemical markers) | 0.685 (0.511 to 0.818) | 0.188 | 90.8 | 0.849 (0.277 to 1.422) | 0.112 | 88.6 | 0.010 (–0.856 to 0.876) | 0.276 | 96.5 |
TABLE 47
Second-trimester models for any pre-eclampsia
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Variable | Original biochemical markers | Ln(biochemical markers) |
---|
Beta coefficient (95% CI) | OR (95% CI) | p-value | Beta coefficient (95% CI) | OR (95% CI) | p-value |
---|
Age (years) | –0.019 (–0.034 to –0.004) | 0.981 (0.966 to 0.996) | 0.012 | –0.026 (–0.041 to –0.011) | 0.974 (0.960 to 0.989) | 0.001 |
SBP | 0.019 (0.009 to 0.029) | 1.019 (1.009 to 1.030) | < 0.001 | 0.005 (–0.005 to 0.015) | 1.005 (0.995 to 1.015) | 0.357 |
DBP | –0.009 (–0.021 to 0.004) | 0.991 (0.979 to 1.004) | 0.167 | 0.020 (0.006 to 0.033) | 1.020 (1.006 to 1.034) | 0.004 |
BMI | 0.069 (0.055 to 0.084) | 1.072 (1.057 to 1.088) | < 0.001 | 0.069 (0.055 to 0.084) | 1.072 (1.057 to 1.087) | < 0.001 |
Nulliparous | 2.099 (1.263 to 2.935) | 8.156 (3.534 to 18.820) | < 0.001 | 2.144 (1.344 to 2.944) | 8.532 (3.833 to 18.993) | < 0.001 |
Previous PE | 1.831 (1.013 to 2.648) | 6.237 (2.755 to 14.123) | < 0.001 | 1.947 (1.172 to 2.722) | 7.006 (3.227 to 15.209) | < 0.001 |
Renal disease | 1.423 (0.609 to 2.237) | 4.150 (1.838 to 9.368) | 0.001 | 1.467 (0.658 to 2.275) | 4.335 (1.931 to 9.732) | < 0.001 |
Hypertension | 2.401 (2.120 to 2.682) | 11.034 (8.334 to 14.608) | < 0.001 | 2.389 (2.112 to 2.666) | 10.905 (8.268 to 14.383) | < 0.001 |
PlGF | –0.003 (–0.004 to –0.002) | 0.997 (0.996 to 0.998) | < 0.001 | –0.539 (–0.658 to –0.420) | 0.583 (0.518 to 0.657) | < 0.001 |
Intercept | –7.895 (–9.314 to –6.476) | | | –6.070 (–7.559 to –4.581) | | |
TABLE 48
Performance statistics for second-trimester models for any pre-eclampsia
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Model | C-statistic | Calibration slope | Calibration-in-the-large |
---|
Estimate (95% CI) | τ2 (for logit C-statistic) | I2 (for logit C-statistic) | Estimate (95% CI) | τ2 | I2 | Estimate (95% CI) | τ2 | I2 |
---|
Original biochemical markers | 0.754 (0.526 to 0.894) | 0.151 | 92.4 | 0.961 (0.358 to 1.564) | 0.052 | 88.7 | 0.004 (–1.284 to 1.293) | 0.262 | 98.0 |
Ln(biochemical markers) | 0.746 (0.521 to 0.888) | 0.150 | 93.6 | 0.945 (0.218 to 1.672) | 0.081 | 94.1 | 0.001 (–1.859 to 1.862) | 0.556 | 99.0 |
TABLE 49
Second-trimester models for early pre-eclampsia
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Variable | Original biochemical markers | Ln(biochemical markers) |
---|
Beta coefficient (95% CI) | OR (95% CI) | p-value | Beta coefficient (95% CI) | OR (95% CI) | p-value |
---|
DBP | 0.071 (0.044 to 0.099) | 1.074 (1.045 to 1.104) | < 0.001 | 0.065 (0.039 to 0.092) | 1.068 (1.039 to 1.096) | < 0.001 |
Previous PE | 1.998 (1.046 to 2.949) | 7.371 (2.847 to 19.084) | < 0.001 | 2.360 (1.529 to 3.191) | 10.594 (4.615 to 24.318) | < 0.001 |
Renal disease | 2.291 (0.151 to 4.431) | 9.883 (1.163 to 83.975) | 0.036 | 3.148 (0.961 to 5.335) | 23.285 (2.613 to 207.474) | 0.005 |
Autoimmune disease | 1.012 (–1.075 to 3.100) | 2.752 (0.341 to 22.193) | 0.342 | 1.154 (–0.924 to 3.231) | 3.169 (0.397 to 25.315) | 0.277 |
sFlt-1 | | | | 0.458 (0.096 to 0.820) | 1.581 (1.100 to 2.271) | 0.013 |
PlGF | –0.003 (–0.005 to –0.001) | 0.997 (0.995 to 0.999) | 0.010 | –0.988 (–1.283 to –0.693) | 0.372 (0.277 to 0.500) | < 0.001 |
Intercept | –10.116 (–12.119 to –8.114) | | | –9.343 (–12.661 to –6.025) | | |
TABLE 50
Performance statistics for second-trimester models for early pre-eclampsia
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Model | C-statistic | Calibration slope | Calibration-in-the-large |
---|
Estimate (95% CI) | τ2 (for logit C-statistic) | I2 (for logit C-statistic) | Estimate (95% CI) | τ2 | I2 | Estimate (95% CI) | τ2 | I2 |
---|
Original biochemical markers | 0.786 (0.389 to 0.955) | 0.304 | 61.2 | 1.054 (0.475 to 1.633) | 0 | 0 | 0.024 (–1.308 to 1.357) | 0.229 | 80.9 |
Ln(biochemical markers) | 0.830 (0.629 to 0.934) | 0.041 | 17.4 | 1.079 (0.567 to 1.591) | 0.011 | 26.0 | 0.099 (–0.972 to 1.169) | 0.107 | 66.4 |
TABLE 51
Second-trimester models for late pre-eclampsia
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Variables | Original biochemical markers | Ln(biochemical markers) |
---|
Beta coefficient (95% CI) | OR (95% CI) | p-value | Beta coefficient (95% CI) | OR (95% CI) | p-value |
---|
Age (years) | –0.020 (–0.036 to –0.004) | 0.980 (0.965 to 0.996) | 0.012 | –0.027 (–0.043 to –0.012) | 0.973 (0.958 to 0.989) | 0.001 |
SBP | 0.018 (0.008 to 0.029) | 1.018 (1.008 to 1.029) | 0.001 | 0.002 (–0.009 to 0.014) | 1.002 (0.991 to 1.014) | 0.697 |
DBP | –0.014 (–0.028 to –0.001) | 0.986 (0.973 to 0.999) | 0.031 | 0.018 (0.002 to 0.033) | 1.018 (1.002 to 1.034) | 0.026 |
BMI | 0.073 (0.058 to 0.088) | 1.076 (1.060 to 1.093) | < 0.001 | 0.074 (0.059 to 0.089) | 1.077 (1.061 to 1.093) | < 0.001 |
Nulliparous | 2.539 (1.564 to 3.515) | 12.673 (4.777 to 33.622) | < 0.001 | 2.567 (1.647 to 3.487) | 13.023 (5.190 to 32.681) | < 0.001 |
Previous PE | 1.734 (0.799 to 2.669) | 5.664 (2.223 to 14.431) | < 0.001 | 1.839 (0.962 to 2.716) | 6.291 (2.617 to 15.120) | < 0.001 |
Renal disease | 1.303 (0.463 to 2.143) | 3.680 (1.588 to 8.524) | 0.002 | 1.318 (0.487 to 2.148) | 3.735 (1.628 to 8.572) | 0.002 |
Hypertension | 2.432 (2.144 to 2.720) | 11.380 (8.531 to 15.180) | < 0.001 | 2.426 (2.144 to 2.709) | 11.317 (8.531 to 15.012) | < 0.001 |
PlGF | –0.003 (–0.004 to –0.002) | 0.997 (0.996 to 0.998) | < 0.001 | –0.424 (–0.545 to –0.302) | 0.655 (0.580 to 0.739) | < 0.001 |
Intercept | –8.054 (–9.598 to –6.510) | | | –6.760 (–8.323 to –5.198) | | |
TABLE 52
Performance statistics for second-trimester models for late pre-eclampsia
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Model | C-statistic | Calibration slope | Calibration-in-the-large |
---|
Estimate (95% CI) | τ2 (for logit C-statistic) | I2 (for logit C-statistic) | Estimate (95% CI) | τ2 | I2 | Estimate (95% CI) | τ2 | I2 |
---|
Original biochemical markers | 0.746 (0.493 to 0.898) | 0.181 | 93.2 | 0.936 (0.355 to 1.517) | 0.047 | 86.5 | 0.004 (–1.295 to 1.303) | 0.266 | 97.8 |
Ln(biochemical markers) | 0.730 (0.477 to 0.889) | 0.180 | 94.4 | 0.909 (0.186 to 1.632) | 0.078 | 92.8 | 0.001 (–1.697 to 1.700) | 0.461 | 98.7 |