Table II.
Characteristics of Participants in Four NHANES Phases*
| Characteristics | 1988–1991(n=9901) | 1991–1994 (n=9717) | 1999–2000 (n=5448) | 2001–2002 (n=5993) |
|---|---|---|---|---|
| Interviewed but not examined (n [%]) | 1076 (11) | 790 (8) | 472 (9) | 401 (6.7) |
| Age (mean [SE]) (yr) | 43.4 (0.4) | 44.1 (0.6) | 44.0 (0.3) | 44.4 (0.5) |
| Age group (%) (yr) | ||||
| 18–39 | 40 | 43 | 42 | 42.0 |
| 40–59 | 25 | 25 | 25 | 27 |
| ≥60 | 35 | 32 | 34 | 31 |
| Women (%) | 52 | 52 | 52 | 52 |
| Race/ethnicity (%) | ||||
| Non‐Hispanic white | 77 | 75 | 70 | 71.5 |
| Non‐Hispanic black | 11 | 11 | 11 | 11.2 |
| Mexican American | 5 | 5 | 7 | 7.3 |
| Other | 7 | 9 | 12 | 9.9 |
| Body mass index (mean [SE]) (kg/m2) | 26.1 (0.1)** | 26.7 (0.1) | 27.8 (0.1) | 27.9 (0.2)** |
| Never had BP checked (%) | 0.6 | 0.3 | 0.5 | 0.8 |
| BP (mean [SE]) (mm Hg) | ||||
| Systolic | 122.0 (0.5) | 122.1 (0.4) | 122.9 (0.4) | 122.0 (0.5) |
| Diastolic | 73.3 (0.2)** | 74.4 (0.3) | 72.1 (0.2) | 71.6 (0.4)** |
| Diabetes mellitus (%) | 5 | 5 | 7 | 6.5 |
| NHANES=National Health and Nutrition Examination Survey; SE=standard error; *data are weighted to the US population; **p<0.05 for differences between 1988–1991 and 2001–2002 | ||||