Table 1.

Diagnostic test accuracy of the alert line for adverse fetal outcomes (fresh stillbirths)

Country (Year) references	Alert line status	Adverse fetal outcome		Percentage of alert line crossing	Prevalence of adverse fetal outcome	Sensitivity (95% CI)	Specificity (95% CI)	Positive likelihood ratio (95% CI)	Negative likelihood ratio (95% CI)	Diagnostic odds ratio (95% CI)	J statistic (95% CI)
		Present	Absent
Senegal (1992)24	Crossed*	5	88	9.3	1.4%	36% (16.3–61.2)	91.1% (89.1–92.7)	4.0 (1.93–8.31)	0.71 (0.48–1.04)	5.67 (1.86–17.29)	26.8% (1.6– 52.0)
	Not crossed**	9	898
Indonesia, Malaysia and Thailand (1994)10	Crossed	0	1532	23.8	0.0%	0 (0–56.2)	76.2% (75.2–77.2)	NA	1.31 (1.3–1.3)	NA	–23.78% (−24.8 to −22.7)
	Not crossed	3	4910
South Africa (2006)26	Crossed	2	461	75.9	0.5%	66.7% (20.6–93.9)	24.1% (20.8–27.6)	0.88 (0.39–1.96)	1.39 (0.28– 6.91)	0.63 (0.06–7.04)	−9.3% (−62.7 to 44.2)
	Not crossed	1	146
Nigeria (2008)28	Crossed	5	208	46.0	1.1%	100% (56.6–100)	54.6% (50.0–59.1)	2.2 (1.99–2.43)	NA	NA	54.6% (50.0– 59.1)
	Not crossed	0	250
Nigeria and Uganda (2018)32	Crossed	30	4133	49.0	0.6%	61.2% (47.3–73.6)	51.0% (50.0–52.1)	1.25 (1.00–1.56)	0.76 (0.53–1.08)	1.65 (0.93–2.93)	12.3% (−1.4 to 24.9)
	Not crossed	19	4307
Overall
Fresh stillbirths	Crossed	42	6422	38.0	0.4%	56.8% (45.4–67.4)	62.1% (61.3–62.8)	1.50 (1.2–1.8)	0.70 (0.5–0.9)	2.15 (1.7–3.4)	18.8% (7.5– 30.1)
	Not crossed	32	10511

NA, not applicable.

*Did not separate fetal death occurring before admission; outcome unknown for five women who crossed the line and two macerated stillbirths excluded from the denominator.

**Outcome unknown for three women who did not cross the line and 12 macerated stillbirths excluded from the denominator.