Table 2.

Performance of the early detection model based on ctDNA methylation in the training and test sets

Patient group	Youden's index best			High specificity			High sensitivity
	Tested	Positive	Positive rate (%)	Tested	Positive	Positive rate (%)	Tested	Positive	Positive rate (%)
Training set
Stage I	34	27	79.4% (62.1–91.2%)	34	23	67.6% (49.4–82.6%)	34	28	82.4% (65.5–93.2%)
Stage II	54	48	88.9% (77.3–95.8%)	54	46	85.2% (72.8–93.4%)	54	48	88.9% (77.4–95.8%)
Stage III	35	32	91.4% (76.9–98.2%)	35	28	80.0% (63.1–91.6%)	35	33	94.3% (80.9–99.3%)
Stage IV	26	25	96.2% (80.3–99.9%)	26	23	88.5% (69.7–97.5%)	26	25	96.2% (80.3–99.9%)
All cancer	149	132	88.6% (82.4–93.2%)	149	120	80.6% (73.2–86.6%)	149	134	89.9% (83.9–94.3%)
Healthy control	149	16	10.7% (6.3–16.9%)	149	8	5.4% (2.4–10.3%)	149	21	14.1% (9.0–20.7%)
Test set
Stage I	17	12	70.6% (43.9–89.6%)	17	11	64.7% (38.2–85.8%)	17	12	70.6% (44.0–89.7%)
Stage II	25	22	88.0% (68.6–97.4%)	25	22	88.0% (68.8–97.5%)	25	22	88.0% (68.6–97.4%)
Stage III	15	13	86.7% (59.6–98.4%)	15	12	80.0% (52.0–95.7%)	15	13	86.7% (59.6–98.4%)
Stage IV	10	9	90.0% (55.2–99.7%)	10	9	90.0% (55.4–99.7%)	10	9	90.0% (55.6–99.7%)
All cancer	67	56	83.6% (72.5–91.6%)	67	54	80.6% (69.1–89.3%)	67	56	83.6% (72.4–91.6%)
Healthy control	74	6	8.1% (3.0–16.8%)	74	3	4.1% (0.8–11.4%)	74	6	8.1% (3.0–16.9%)