Table 1.

Factor levels and type of second-derivative curve in the activated partial thromboplastin time assay

Calculated level of factor (%)	Factor
	V		VIII		IX		XI		XII
Measured level of factor (%)	Type of curve	Measured level of factor (%)	Type of curve	Measured level of factor (%)	Type of curve	Measured level of factor (%)	Type of curve	Measured level of factor (%)	Type of curve
0	0.6	ABN-B	0.3	ABN-B	0.4	ABN-B	0.5	ABN-B	0.4	ABN-S
2	2.5	ABN-S	3.6	ABN-S	5.5	ABN-S	4.1	ABN-S	2.3	N
4	3.9	ABN-S	5.8	ABN-S	6.7	ABN-S	5.8	N	3.8	N
10	10.2	N	11.7	ABN-S	15.1	ABN-S	10.8	N	11.4	N
20	17.7	N	17.9	N	28.5	N	20.9	N	22.7	N
50	46.3	N	48.3	N	64.3	N	46.6	N	52.8	N
80	72.3	N	70.3	N	90.8	N	69.0	N	72.4	N
100	92.8	N	80.7	N	115.7	N	85.0	N	86.4	N

Factor activity was determined in a standard one-stage assay using activated partial thromboplastin time (APTT) SynthASil. APTT assay for waveform analysis was performed using APTT-SP. ‘Type of curve’ indicates the status of the second-derivative curve in the APTT assay. ABN-B, abnormal biphasic-type; ABN-S, abnormal shoulder-type; N, normal.