Demographics of the Sample
| Unweighted N | 8,270 |
| Weighted N | 176,423,413 |
| Ferritin | |
| Elevated | 10.8 |
| Normal | 89.2 |
| Uric acid | |
| Elevated | 17.6 |
| Normal | 82.4 |
| Joint pain | |
| Yes | 44.8 |
| No | 55.2 |
| Age (years) | |
| 20–44 | 50.9 |
| 45–64 | 32.8 |
| ≥65 | 16.3 |
| Sex | |
| Male | 48.1 |
| Female | 51.9 |
| Race/ethnicity | |
| Non-Hispanic white | 72.6 |
| Non-Hispanic black | 10.0 |
| Mexican American | 7.0 |
| Other Hispanic | 6.9 |
| Other race | 3.4 |
Values presentence as percents.