2. Indirect comparisons of the diagnostic accuracy of five urine tests in combination with maternal age.

Ratio of DOR (95% CI); P value			Second trimester AFP and ß‐core fragment to oestriol ratio, risk 1:58	Second trimester ß‐core fragment and oestriol, 5% FPR	Second trimester ITA, 5% FPR	Second trimester ß‐core fragment to oestriol ratio, 5% FPR
		Studies	1	2	1	3
	Studies	DOR (95% CI)	186 (22, 1560)	50 (30 to 84)	43 (17 to 110)	38 (24 to 59)
Second trimester ß‐core fragment and oestriol, 5% FPR	2	50 (30 to 84)	3.7 (0.4 to 33.0); P = 0.24
Second trimester ITA, 5% FPR	1	43 (17 to 110)	4.3 (0.4 to 44.0); P = 0.22	1.2 (0.4 to 3.4); P = 0.78
Second trimester ß‐core fragment to oestriol ratio, 5% FPR	3	38 (24 to 59)	4.9 (0.6 to 43.4); P = 0.15	1.3 (0.7 to 2.6); P = 0.41	1.1 (0.4 to 3.2); P = 0.80
Second trimester ß‐core fragment, 5% FPR	5	25 (18 to 36)	7.3 (0.8 to 63.1); P = 0.07	2.0 (1.1 to 3.7); P = 0.03	1.7 (0.6 to 4.6); P = 0.30	1.5 (0.8 to 2.6); P = 0.18

Indirect comparisons were made using all available data. Ratio of diagnostic odds ratios (DOR)s were computed by division of the DOR for the test in the column by the DOR for the test in the row. If the ratio of DORs is greater than one, then the diagnostic accuracy of the test in the column is higher than that of the test in the row; if the ratio is less than one, the diagnostic accuracy of the test in the row is higher than that of the test in the column.

AFP: alpha‐fetoprotein; CI: confidence interval; DORs: diagnostic odds ratio; FPR: false positive rate; ITA: invasive trophoblast antigen