Table 3.

Classification of BCSP study participants using GC–IMS using Gaussian process or support vector machine

Group	AUC	Sensitivity	Specificity	PPV	NPV
CRC (10) vs normal (24)	0.82 (0.67–0.97)	0.80 (0.44–0.97)	0.83 (0.63–0.95)	0.67	0.91
CRC + high-risk adenomas (23) vs normal(24)	0.53 (0.36–0.70)	0.48 (0.27–0.69)	0.67 (0.45–0.84)	0.58	0.57
CRC (10) vs other (20)	0.77 (0.60–0.94)	1 (0.66-1)	0.57 (0.34–0.78)	0.5	1
CRC + all adenomas (65) vs other (42)	0.61 (0.49–0.72)	0.71 (0.58–0.81)	0.55 (0.39–0.70)	0.71	0.55
All adenomas (55) vs normal (24)	0.61 (0.47–0.75)	0.58 (0.44–0.71)	0.62 (0.41–0.81)	0.78	0.39

Corresponding 95% CI are in brackets. Study numbers are stated in the group column in brackets

BSCP bowel cancer screening programme, GC–IMS gas chromatography coupled with ion mobility spectrometry, AUC area under the curve, CRC colorectal cancer, PPV positive predictive value, NPV negative predictive value