Table 4.
Final new model.
| Coefficient | Unadjusted coefficient* | Standard error | Adjusted coefficient | Adjusted Odds ratio* |
|---|---|---|---|---|
| Intercept | -3·651 | 0·261 | -3·593 | |
| Number of antenatal care visits⁎⁎ | -0·112 | 0·062 | -0·105 | 0·894 |
| Hypertensive disorders | ||||
| No hypertensive disorders | Reference category | |||
| Mild hypertension | 0·128 | 0·252 | 0·120 | 1·137 |
| Severe hypertension | 0·720 | 0·180 | 0·677 | 2·054 |
| Sickle cell anaemia | 2·649 | 1·003 | 2·491 | 14·139 |
| Other comorbidities†,⁎⁎⁎ | 0·723 | 0·434 | 0·680 | 2·062 |
| Gestational age | ||||
| Term | Reference category | |||
| very preterm | 1·780 | 0·255 | 1·674 | 5·931 |
| mild-moderate preterm | 0·177 | 0·196 | 0·167 | 1·194 |
| Post-term | 0·297 | 0·331 | 0·280 | 1·346 |
| Fundal height | ||||
| Normal | Reference category | |||
| Small | 0·749 | 0·178 | 0·704 | 2·115 |
| Large | 0·353 | 0·230 | 0·332 | 1·424 |
| Abnormal/non-reassuring FHR | 2·520 | 0·296 | 2·370 | 12·425 |
| Rupture of membranes >24hours | 0·916 | 0·437 | 0·862 | 2·500 |
| Meconium-staining of amniotic fluid | 1·237 | 0·486 | 1·163 | 3·445 |
| Maternal perception of foetal movement | ||||
| Normal | Reference category | |||
| Reduced | 1·060 | 0·177 | 0·997 | 2·885 |
| Absent | 1·830 | 0·440 | 1·721 | 6·236 |
| Unsure | 0·759 | 0·241 | 0·714 | 2·137 |
| Bleeding | 3·322 | 0·334 | 3·124 | 27·720 |
| Grand-multiparity (≥5 parity) | 0·059 | 0·209 | 0·055 | 1·061 |
| Previous scar | 0·403 | 0·283 | 0·379 | 1·497 |
| Abnormal presentation | 0·056 | 0·388 | 0·053 | 1·058 |
| Multiple pregnancy | 0·621 | 0·266 | 0·584 | 1·860 |
Unadjusted coefficient. denotes coefficient before shrinkage; Adjusted denotes coefficient after shrinkage.
Odds ratio per one antenatal care visit.
Odds ratio per comorbidity.
Other comorbidities: diabetes, HIV, thyroid disease, renal disease, syphilis
Model specification:
Risk of perinatal death = 1/(1+exp (-(-3·593 + -0·105 *(Number of antenatal care visits)+ 0·120 * (Mild hypertension) + 0·677 * (Severe hypertension) + 2·491 * (Sickle cell anaemia) + 0·680 * (Other comorbidities) + 1·674 * (very preterm) + 0·167*(Mild-moderate preterm) + 0·280 * (post-term) +0·704 * (small) + 0·332 * (large) + 2·370 * (Abnormal Foetal heart rate) + 0·862 * (rupture of membranes >24hours) + 1·163 * (meconium-staining of amniotic fluid) + 0·997 * (Reduced foetal movement) + 1·721 * (Absent foetal movement) + 0·714 * (Unsure of foetal movement) + 3·124 * (Bleeding) + 0·055 * (grand-multiparity) + 0·379 * (Previous scar) + 0·053 * (Abnormal presentation) + 0·584 * (Multiple pregnancy))))
Worked example: for a para 6 with 4 antenatal care visits who presented at term with preeclampsia, history of bleeding and reduced foetal movement
Risk of perinatal death = 1/(1+exp(-(-3·593 + (-0·105 * 4 + 0·120*0 + 0·677*1 + 2·491*0 + 0·680*0 + 1·674*0 + 0·167*0 + 0·280*0 + 0·704*0 + 0·332*0+ 2·370*0+ 0·862*0+ 1·163*0+ 0·997*1 + 1·721* 0+ 0·714*0 + 3·124*1+ 0·055* 1+ 0·379*0 + 0·053*0 + 0·584*0))))
=1/(1+exp (-0·84))
Risk of perinatal death = 0·70, which corresponds to 70%.