Table 1 Basic characteristics of the study participants by folate level
From: Serum folate concentration and health-related quality of life among the elderly in South Korea
Characteristic | Tertiles of folate level (range, ng/mL) | P | ||
|---|---|---|---|---|
T1 (4.3, 1.7–5.6) | T2 (7.1, 5.7–9.4) | T3 (12.4, 9.5–31.9) | ||
Participants, n | 339 | 348 | 334 | Â |
Age, years | 73.2 (0.4) | 72.4 (0.3) | 72.7 (0.3) | 0.20 |
Female, % | 38.3 (3.1) | 53.9 (3.0) | 67.2 (2.8) |  < 0.001 |
Marital status (married & living together), % | 66.5 (3.0) | 66.3 (3.1) | 61.3 (3.3) | 0.40 |
Socioeconomic status variables | ||||
 Education level, % |  |  |  | 0.039 |
   ≤ Middle school | 70.1 (3.0) | 73.3 (2.8) | 64.7 (3.3) |  |
  High school | 19.6 (2.5) | 18.9 (2.5) | 18.9 (2.6) |  |
   ≥ College | 10.4 (2.0) | 7.7 (1.6) | 16.5 (2.3) |  |
 Employment status, % |  |  |  | 0.002 |
  Employed | 29.7 (2.9) | 37.8 (3.2) | 23.5 (2.6) |  |
  Unemployed | 70.3 (2.9) | 62.2 (3.2) | 76.5 (2.6) |  |
 Household income, % |  |  |  | 0.12 |
  Low | 47.2 (3.5) | 46.4 (3.4) | 43.8 (3.3) |  |
  Lower middle | 27.9 (3.1) | 27.6 (3.0) | 23.1 (2.5) |  |
  Upper middle | 17.6 (2.8) | 16.1 (2.5) | 17.5 (2.5) |  |
  High | 7.3 (1.6) | 9.9 (1.9) | 15.7 (2.4) |  |
Lifestyle variables | ||||
 Current smoking, % | 15.5 (2.2) | 6.7 (1.7) | 4.9 (1.3) |  < 0.001 |
 Alcohol consumption (≥ 1 drink/month), % | 42.6 (3.2) | 36.6 (2.9) | 26.8 (2.6) | 0.001 |
 Aerobic physical activity, % | 27.1 (2.8) | 32.5 (2.9) | 37.4 (3.1) | 0.040 |
Disease variables | ||||
 BMI, mean | 23.9 (0.2) | 24.2 (0.2) | 24.0 (0.2) | 0.53 |
 Diabetes mellitus, % | 30.2 (3.2) | 26.4 (2.7) | 23.8 (2.6) | 0.30 |
 Hypertension, % | 68.1 (2.7) | 62.2 (3.2) | 62.8 (3.0) | 0.30 |
 Dyslipidemia, % | 55.1 (3.2) | 54.3 (3.0) | 57.7 (3.1) | 0.73 |
HRQOL (score of EQ-5D) | 0.866 (0.01) | 0.877 (0.01) | 0.887 (0.01) | 0.30 |
Problem in dimensions, % | ||||
 Mobility | 40.4 (3.2) | 37.2 (3.3) | 34.7 (3.2) | 0.44 |
 Self-care | 14.2 (2.2) | 10.2 (1.9) | 8.5 (1.6) | 0.09 |
 Usual activities | 22.3 (2.4) | 21.7 (2.9) | 22.2 (2.6) | 1.00 |
 Pain/discomfort | 36.9 (3.2) | 37.0 (3.2) | 38.4 (3.0) | 0.94 |
 Anxiety/depression | 15.8 (2.5) | 17.6 (2.4) | 15.2 (2.0) | 0.74 |