Table 26.

Best results for classifiers without using feature selection (kNN*) and after using feature selection (BPSO-kNN*) in terms of accuracy, number of features, and improvement rate.

Dataset	KNN*		BPSO-KNN		Improvement Rate
	Accuracy	No. Features	Accuracy	No. Features	Features Reduction	Accuracy
All	0.7409	31	0.7628	18	41.94%	2.19%
Caucasion	0.7483	30	0.8080	13	56.67%	5.96%
Hispanic	0.7724	30	0.7968	14	53.33%	2.44%
Females	0.7373	30	0.8136	13	56.67%	7.63%
Males	0.6987	30	0.7885	11	63.33%	8.97%
Age ≤ 50	0.7431	31	0.8624	15	51.61%	11.93%
Age > 50	0.7333	31	0.8061	17	45.16%	7.27%