Prediction of pre-eclampsia in nulliparous women using routinely collected maternal characteristics: a model development and validation study

Table 3 Comparison of the NICE approach versus the WS model for predicting pre-eclampsia in nulliparous women

Approach	Threshold	≥Threshold n (%)	Sensitivity (95% CI)	Specificity (95% CI)	PPV (95% CI)	NPV (95% CI)	Positive LR (95% CI)	Negative LR (95% CI)	NNT	NNS
Women without high-risk factors, n = 12,125
NICE approach	Screen-positive^a	903 (7.4)	28% (23–34%)	93% (93–94%)	8% (7–10%)	98% (98–99%)	4.07 (3.32–4.99)	0.77 (0.71–0.83)	122	1639
WS base model	3.9%^b	912 (7.5)	29% (24–35%)	93% (92–93%)	8% (7–10%)	98% (98–99%)	4.15 (3.40–5.07)	0.76 (0.70–0.82)	120	1595
All women, n = 12,395
NICE approach	Screen-positive^a	1173 (9.5)	37% (31–42%)	91% (91–92%)	9% (8–11%)	98% (98–99%)	4.15 (3.53–4.87)	0.70 (0.64–0.76)	110	1158
WS final model	3.8%^b	1205 (9.7)	38% (33–44%)	91% (90–91%)	9% (8–11%)	98% (98–99%)	4.23 (3.62–4.95)	0.68 (0.62–0.74)	108	1107

^aNICE approach screen-positive if ≥1 high-risk factors or ≥ 2 moderate-risk factors. High-risk factors included in this analysis: chronic renal disease, diabetes (type 1 or 2), chronic hypertension and autoimmune disease. Moderate-risk factors included in this analysis: first pregnancy, age ≥ 40 year, body mass index ≥35 kg/m², family history of pre-eclampsia and multiple pregnancy
^bModel risk cut-off when the model specificity is fixed at the level of the NICE approach
CI Confidence interval, LR Likelihood ratio, NICE National Institute for Health and Care Excellence, NNS Number needed to screen, NNT Number needed to treat, NPV Negative predictive value, PPV Positive predictive value, WS Western Sydney

ISSN: 1471-2393