Table 1. Descriptive Statistics for Sample and Population Estimates.
95% CI = 95% confidence interval
| Variable | Unweighted Count | % | Population Estimate | Standard Error | 95% CI Lower Bound | 95% CI Upper Bound |
| Back Pain | ||||||
| Yes | 10,078 | 28.0 | 65,823,057 | 965,737 | 63,922,579 | 67,723,534 |
| No | 24,427 | 72.0 | 168,937,180 | 1,844,349 | 165,307,679 | 172,566,680 |
| Total | 34,505 | 100.0 | 234,760,237 | 2,291,291 | 230,251,198 | 239,269,275 |
| Smoking | ||||||
| Current | 6,436 | 18.1 | 42,098,139 | 813,046 | 40,498,141 | 43,698,136 |
| Former | 7,584 | 22.2 | 51,621,850 | 865,475 | 49,918,678 | 53,325,021 |
| Never | 20,236 | 59.8 | 139,327,445 | 1,617,264 | 136,144,825 | 142,510,064 |
| Total | 34,256 | 100.0 | 233,047,434 | 2,287,231 | 228,546,384 | 237,548,483 |
| Sex | ||||||
| Male | 15,273 | 44.2 | 113,070,897 | 1,471,455 | 110,175,215 | 115,966,578 |
| Female | 19,252 | 55.8 | 121,849,773 | 1,395,324 | 119,103,909 | 124,595,636 |
| Total | 34,525 | 100.0 | 234,920,670 | 2,292,625 | 230,409,005 | 239,432,334 |
| Race | ||||||
| Hispanic | 5,859 | 14.9 | 34,946,432 | 816,213 | 33,340,203 | 36,552,660 |
| Non-Hispanic White | 20,842 | 67.2 | 157,787,860 | 2,071,449 | 153,711,448 | 161,864,271 |
| Non-Hispanic Black | 5,282 | 11.9 | 27,885,414 | 626,598 | 26,652,329 | 29,118,498 |
| Non-Hispanic Asian | 2,168 | 5.3 | 12,415,030 | 424,711 | 11,579,238 | 13,250,821 |
| Non-Hispanic All Other | 372 | 0.8 | 1,885,934 | 198,313 | 1,495,671 | 2,276,196 |
| Total | 34,525 | 100.0 | 234,920,670 | 2,292,625 | 230,409,005 | 239,432,334 |