Table 5 Factor structure of the SF-12 derived from principal component analysis*

Physical functioning (PF)

Limitations in moderate physical activities (PF1)

0.75

0.07

Limitations in climbing several flights of stairs (PF2)

0.74

0.10

Role physical (RP)

Accomplished less due to physical health (RP1)

0.67

0.26

Limited in kind of work or activities due to physical health (RP2)

0.72

0.23

Bodily pain (BP)

Pain interference with work inside or outside home (PB1)

0.48

0.30

General health (GH)

Health rating in general (GH1)

0.51

0.34

Social functioning (SF)

Interference of physical health or e-motional problems with social activities (SF1)

0.38

0.60

RE

Accomplished less due to emotional problems (RE1)

0.27

0.61

Not careful in work or activities due to emotional problems (RE2)

0.32

0.60

Vitality (VT)

Having a lot of energy (VT1)

0.22

0.61

MH

Feel calm and peaceful (MH1)

0.07

0.70

Feel down hearted and blue (MH2)

0.05

0.71

Eigenvalues

4.52

1.27

Variance explained (%)

37.7

20.1