Table 1 Distribution of item responses (%) for the SF-36 sub-scale items
Item | Response option | |||||
Physical Functioning (NÂ =Â 9337) | Limited a lot | Limited a little | Not limited at all | |||
 PF1: Vigorous activities | 43.9 | 34.2 | 21.9 | |||
 PF2: Moderate activities | 12.7 | 24.4 | 62.9 | |||
 PF3: Lifting or carrying groceries | 9.1 | 22.2 | 68.8 | |||
 PF4: Climbing several flights of stairs | 15.2 | 29.6 | 55.1 | |||
 PF5: Climbing one flight of stairs | 5.6 | 15.8 | 78.6 | |||
 PF6: Bending, kneeling or stooping | 13.0 | 33.0 | 54.0 | |||
 PF7: Walking more than a mile | 16.5 | 20.6 | 62.9 | |||
 PF8: Walking several blocks | 10.8 | 15.0 | 74.2 | |||
 PF9: Walking one block | 4.0 | 9.9 | 86.0 | |||
 PF10: Bathing or dressing self | 2.0 | 6.5 | 91.5 | |||
Mental Health (NÂ =Â 9395) | All of the time | Most of the time | Good bit of the time | Some of the time | Little of the time | None of the time |
Have you… |  |  |  |  |  |  |
 MH1: Been a very nervous person? | 1.3 | 3.1 | 5.4 | 17.2 | 29.7 | 43.3 |
 MH2: Felt so down in the dumps that nothing could cheer you up? | 0.3 | 1.1 | 1.8 | 7.4 | 17.0 | 72.4 |
 MH3: Felt calm and peaceful? | 10.6 | 46.3 | 18.2 | 15.7 | 5.9 | 3.2 |
 MH4: Felt downhearted and blue? | 0.4 | 1.6 | 3.4 | 17.8 | 34.8 | 42.1 |
 MH5: Been a happy person? | 18.5 | 54.8 | 12.9 | 8.7 | 2.9 | 2.3 |