Table 1. Baseline characteristics by income groups.
| Low income | Medium Income | High Income | P a | |
| PIR ≤1.30 | 1.3 <PIR <3.5 | PIR ≥ 3.50 | ||
| N = 2617 | N = 3855 | N = 3453 | ||
| Demographic | ||||
| Age, mean (SE) | 42.73 (0.46) | 45.75 (0.42) | 46.15 (36) | <.0001 |
| Sex | <.0001 | |||
| Female | 1440 (55) | 1986 (52) | 1693 (49) | |
| Male | 1177 (45) | 1869 (48) | 1760 (51) | |
| Race/ethnicity | <.0001 | |||
| Non-Hispanic Black | 555 (21) | 744 (19) | 479 (14) | |
| Mexican American | 884 (34) | 965 (25) | 381 (11) | |
| Other | 259 (10) | 258 (7) | 177 (5) | |
| Non-Hispanic White | 919 (35) | 1888 (49) | 2416 (70) | |
| Education | <.0001 | |||
| <High school | 1430 (55) | 1181 (31) | 300 (9) | |
| High school/some college | 1060 (41) | 2183 (57) | 1759 (51) | |
| ≥ College graduate | 127 (5) | 491 (13) | 1394 (40) | |
| Health behaviors | ||||
| BMI (kg/m2) | <.0001 | |||
| ≥40.0 | 151 (6) | 182 (5) | 135 (4) | |
| 30.0–39.9 | 733 (28) | 1060 (27) | 892 (26) | |
| 25.0–29.9 | 891 (34) | 1421 (37) | 1289 (37) | |
| 18.5–24.9 | 797 (30) | 1134 (29) | 1094 (32) | |
| <18.5 | 45 (2) | 58 (2) | 43 (1) | |
| MET-hours/week of leisure-time physical activity | <.0001 | |||
| Inactive (0) | 1450 (55) | 1701 (44) | 893 (26) | |
| Somewhat active (>0 to <9) | 698 (27) | 1159 (30) | 1130 (33) | |
| Active (≥9) | 469 (18) | 995 (26) | 1430 (41) | |
| Diet (HEI-2005 quintiles) | <.0001 | |||
| Q1 | 615 (24) | 784 (20) | 585 (17) | |
| Q2 | 557 (21) | 774 (20) | 645 (19) | |
| Q3 | 525 (20) | 806 (21) | 664 (19) | |
| Q4 | 508 (19) | 774 (20) | 711 (21) | |
| Q5 | 412 (16) | 717 (19) | 848 (24) | |
| Current smoking | <.0001 | |||
| Yes | 782 (30) | 866 (22) | 532 (15) | |
| No | 1835 (70) | 2989 (78) | 2921 (85) | |
| Alcohol use | <.0001 | |||
| Non-drinker | 1347 (51) | 1702 (44) | 1035 (30) | |
| Moderate drinker | 1117 (43) | 1899 (49) | 2150 (62) | |
| Heavy drinker | 153 (6) | 254 (7) | 268 (8) | |
| Access to care | ||||
| Insurance coverage | <.0001 | |||
| Yes | 1686 (64) | 3038 (79) | 3265 (95) | |
| No | 931 (36) | 817 (21) | 188 (5) | |
| Health status | ||||
| Self-rated health | <.0001 | |||
| Good | 1753 (67) | 3085 (80) | 3155 (91) | |
| Fair/poor | 864 (33) | 770 (20) | 298 (9) | |
| Disabilities, Yes (vs. No) | ||||
| ADL | 293 (11) | 225 (6) | 126 (4) | <.0001 |
| IADL | 402 (15) | 309 (8) | 189 (5) | <.0001 |
| LSA | 292 (11) | 217 (6) | 118 (3) | <.0001 |
| LEM | 397 (15) | 352 (9) | 160 (5) | <.0001 |
| GPA | 552 (21) | 552 (14) | 374 (11) | <.0001 |
| Biological | ||||
| CRP, mg/L | <.0001 | |||
| <1 | 610 (23) | 945 (25) | 1025 (30) | |
| 1–3 | 826 (32) | 1338 (35) | 1179 (34) | |
| >3–10 | 826 (32) | 1154 (30) | 929 (27) | |
| >10 | 355 (14) | 418 (11) | 320 (9) |
Abbreviations: ADL: Activities of daily living; BMI: Body mass index; CRP: C-reactive protein; CVD: Cardiovascular disease; GPA: General physical activities; HEI: Healthy eating index; IADL: Instrumental activities of daily living; LEM: Lower extremity mobility; LSA: Leisure and social activities; PIR: Poverty-income ratio.
Data are N (%) unless otherwise indicated. a χ2 (chi-square) analysis was used to compare frequencies and ANOVA was used to compare mean age between groups.