Table 2.

Matrix of rotated principal components of variables included in the GPM-24 scale

Item	Subscale	Component
		1	2	3	4	5	6
	Disengagement because of pain
9	Limited time for work or other activities			0.53		0.35
10	Achieving less than expected			0.48
11	Restriction of the type of work or other activities			0.70
12	Need to make an extra effort at work or during other activities			0.57
15	Lack of enjoyment of social gatherings or other recreational activities	0.38	0.32
18	Relying on family members or friends for help because of pain			0.72
24	Feelings of sadness or depression			0.73
	Pain intensity
13	Trouble sleeping				0.82
17	Feeling tired physically or mentally			0.38	0.42
19	Intensity of pain that is usually experienced						− 0.60
20	Average pain intensity level over the last 7 days						− 0.81
21	Never completely disappears						− 0.68
22	Experienced every day						− 0.67
23	Experienced a few times a week					0.89
	Pain with ambulation
4	Walking up the stairs more than one floor		− 0.52
5	Walking up the stairs more than a few steps	0.83
6	Walking further than one block	0.51	− 0.45
7	Walking one block or a shorter distance	0.85
	Pain with strenuous activities
1	Vigorous movement		− 0.83
2	Limiting strenuous activities		− 0.77
3	Lifting/carrying grocery shopping		− 0.45
	Pain with other activities
8	Bathing or getting dressed	0.80
14	Inability to participate in religious services		0.31				− 0.34
16	Lack of possibility to travel or use standard means of transport			0.39

From the PCA table, all the factor loadings below 0.4 were removed for a clear presentation of the factor structure of the analysed scale