Table 3.

Summary of statistical difference between actual and machine learning results.

	Mean absolute error			STD
	Saliva		Armpit	Saliva		Armpit
Number of data	48	28	28	48	28	28
Random forest	5.83	5.82	4.39	3.07	3.50	3.71
Decision tree	5.22	4.54	4.82	3.53	3.42	3.55
Ordinal regression	3.50	3.92	4.34	2.26	2.73	3.01
KNN	4.10	3.62	3.60	3.57	2.27	2.24