Sex (Men or Women)
1 = Men
2 = Women

GHQ_1
0 = Better than usual
1 = Same as usual
2 = Less than usual
3 = Much less than usual

GHQ_2
0 = No, not at all
1 = No more than usual
2 = More than the usual
3 = Much more than usual

GHQ_3
0 = More useful than usual
1 = Same as usual
2 = Less than usual
3 = More less than usual

GHQ_4
0 = More than usual
1 = Same as usual
2 = Less than usual
3 = More less than usual

GHQ_5
0 = No, not at all
1 = No more than usual
2 = Some more than usual
3 = Much more than usual

GHQ_8
0 = More able than usual
1 = Same as usual
2 = Less able than usual
3 = More less able than usual

GHQ_10
0 = No, not at all
1 = No more than usual
2 = Some more than suaual
3 = Much more than usual

GHQ_12
0 = More than usual
1 = Same than usual
2 = Less than usual
3 = Much more than usual

Social Class (I_VI)
1 = I
2 = II
3 = III
4 = IV
5 = V
6 = VI

Physical Activity Level
1 = Inactive
2 = Walkers
3 = Active
4 = Very active

Self Perceived Health
1 = Positive
2 = Fair
3 = Negative

Depression
0 = No
1 = Yes