Table A2.

Characteristics of populations defined by different cut‐off values for A10, where predicted event is massive transfusion (21 cases)

A10	Positive test	% testing positive	TP	FP	TN	FN	Sensitivity	Specificity	PPV	NPV	Youden's index
< 25	25	2.2	8	17	1108	13	0.38	0.98	0.32	0.99	0.37
< 26	26	2.3	8	18	1107	13	0.38	0.98	0.31	0.99	0.36
< 27	26	2.3	8	18	1107	13	0.38	0.98	0.31	0.99	0.36
< 28	27	2.4	8	19	1106	13	0.38	0.98	0.30	0.99	0.36
< 29	30	2.6	8	22	1103	13	0.38	0.98	0.27	0.99	0.36
< 30	34	3.0	8	26	1099	13	0.38	0.98	0.24	0.99	0.36
< 31	34	3.0	8	26	1099	13	0.38	0.98	0.24	0.99	0.36
< 32	37	3.2	10	27	1098	11	0.48	0.98	0.27	0.99	0.45
< 33	43	3.8	10	33	1092	11	0.48	0.97	0.23	0.99	0.45
< 34	50	4.4	11	39	1086	10	0.52	0.97	0.22	0.99	0.49
< 35	54	4.7	11	43	1082	10	0.52	0.96	0.20	0.99	0.49
< 36	55	4.8	11	44	1081	10	0.52	0.96	0.20	0.99	0.48
< 37	59	5.1	12	47	1078	9	0.57	0.96	0.20	0.99	0.53
< 38	65	5.7	13	52	1073	8	0.62	0.95	0.20	0.99	0.57
< 39	76	6.6	13	63	1062	8	0.62	0.94	0.17	0.99	0.56
< 40	80	7.0	13	67	1058	8	0.62	0.94	0.16	0.99	0.56
< 41	88	7.7	13	75	1050	8	0.62	0.93	0.15	0.99	0.55
< 42	104	9.1	14	90	1035	7	0.67	0.92	0.13	0.99	0.59
< 43	123	10.7	15	108	1017	6	0.71	0.90	0.12	0.99	0.62
< 44	152	13.3	16	136	989	5	0.76	0.88	0.11	0.99	0.64
< 45	183	16.0	18	165	960	3	0.86	0.85	0.10	1.00	0.71
< 46	225	19.6	18	207	918	3	0.86	0.82	0.08	1.00	0.67
< 47	267	23.3	19	248	877	2	0.90	0.78	0.07	1.00	0.68
< 48	317	27.7	19	298	827	2	0.90	0.74	0.06	1.00	0.64
< 49	361	31.5	19	342	783	2	0.90	0.70	0.05	1.00	0.60
< 50	415	36.3	19	396	729	2	0.90	0.65	0.05	1.00	0.55

TP, true positive; FP, false negative; TN, true negative; FN, false negative; PPV, positive predictive value, NPV, negative predictive value; Youden's index = (sensitivity + specificity) –1.