Table 5.

Frequency distribution of video frames in the UNBC-McMaster and DISFA databases by PSPI scores and PSPI groups.

PSPI score	UNBC-McMaster database		DISFA database
	Frequency by PSPI score	Frequency by PSPI group	Frequency by PSPI score	Frequency by PSPI group
0	40,029	2483*	90,309	9025*
1	2909	2909	9973	9973
2	2351	3763	12,194	10,309*
3	1412		8447
4	802	1697	4127	9875
5	242		1661
6	270		1526
7	53		996
8	79		435
9	32		503
10	67		317
11	76		169
12	48		108
13	22		33
14	1		0
15	5		0
Total	48,398	10,852	130,798	39,182

*Random under-sampling of over-represented PSPI groups was performed to create more balanced study datasets with smaller total numbers of video frames for training and testing the pain intensity classification model.