Table 1. Characteristics of actual participants in 2005–2006 and 2007–2008 NHANES.
| All subjects | Non-Glaucoma subjects | Glaucoma subjects | P-value | |
|---|---|---|---|---|
| Total number of subjects | 3864 | 3652 | 212 | |
| Mean age (year±SD) | 56.4±11.3 | 56.1±11.2 | 63.0±11.6 | 0.002 |
| Male gender | 1917 | 1796 (49.2%) | 121 (57.1%) | 0.03 |
| Ethnicity: | <0.001 | |||
| White | 1949 | 1879 (51.5%) | 70 (33.0%) | |
| Black | 831 | 754 (20.7%) | 77 (36.3%) | |
| Hispanic | 934 | 884 (24.2%) | 50 (23.6%) | |
| Others | 150 | 135 (3.7%) | 15 (7.1%) | |
| Educational level: | 0.50 | |||
| Less than ninth grade | 491 | 457 (12.5%) | 34 (16.0%) | |
| Ninth grade to less than high school graduate | 570 | 537 (14.7%) | 33 (15.6%) | |
| High school graduate or general educational development equivalent | 951 | 897 (24.6%) | 54 (25.5%) | |
| Some college | 1005 | 954 (26.1%) | 51 (24.1%) | |
| College graduate and beyond | 846 | 806 (22.1%) | 40 (18.9%) | |
| Annual household income ($): | 0.06 | |||
| <20 000 | 682 | 645 (21.7%) | 37 (22.0%) | |
| 20 000–44 999 | 1124 | 1049 (35.2%) | 75 (44.6%) | |
| 45 000–74 999 | 778 | 746 (25.1%) | 32 (19.1%) | |
| ≥75 000 | 458 | 441 (14.8%) | 17 (10.1%) | |
| ≥ 20 000 | 103 | 96 (3.2%) | 7 (4.2%) | |
| Diabetes Mellitus (self-reported) | 492 | 452 (12.4%) | 40 (18.9%) | 0.006 |
| Hypertension (self-reported) | 1555 | 1449 (39.7%) | 106 (50.5%) | 0.003 |
| Steroid use (self-reported) | 6 | 5 (0.2%) | 1 (0.9%) | 0.23 |
| Body mass index (kg/m2±SD) | 29.2±6.6 | 29.3±6.6 | 28.6±5.5 | 0.97 |
| Alcohol consumption (number of drinks/day±SD) | 1.7±2.5 | 1.8±2.5 | 1.4±1.8 | 0.24 |
| Refractive error (diopters (D), right eye) | 0.50 | |||
| Myopia (≤ −1.00 D) | 882 | 838 (22.9%) | 44 (20.8%) | |
| Emmetropia (−0.99 to 0.99 D) | 2076 | 1964 (53.8%) | 112 (52.8%) | |
| Hyperopia (≥ +1.00 D) | 901 | 845 (23.1%) | 56 (26.4%) | |
| Non-smoker | 1897 | 1801 (49.3%) | 96 (45.3%) | 0.25 |
| Smoker (current and Ex-smoker): | 1967 | 1851 (50.7%) | 116 (54.7%) | |
| Current smoker | 814 | 779 (42.1%) | 35 (30.2%) | 0.01 |
| Ex-Smoker | 1153 | 1072 (57.9%) | 81 (69.8%) | |
| Cotinine (ng/ml±SD) | 62.6±134.3 | 63.2±134.8 | 51.6±124.4 | 0.91 |
| Cup/Disc-ratio (± SD, right eye) | 0.41±0.12 | 0.40±0.11 | 0.59±0.14 | <0.001 |
| Cup/Disc-ratio (± SD, left eye) | 0.41±0.12 | 0.40±0.11 | 0.60±0.14 | <0.001 |
Bold values are statistically significant P-values (i.e. P < 0.05).