Table 2.
Association between serum folic acid and severe difficulty falling asleep, NHANES 2005–2008.
| Model 1 | Model 2 | Model 3 | |
|---|---|---|---|
| OR (95%) | OR (95%) | OR (95%) | |
| Serum folic acid (ng/ml) | 0.99 (0.98, 1.00) | 0.98 (0.97, 1.00) | 0.99 (0.98, 1.00) |
| Serum folic acid (ng/ml, quartile) | |||
| Q1 (0.70–9.50) | Referrence | Referrence | Referrence |
| Q2 (9.50–13.90) | 0.69 (0.52, 0.91) | 0.67 (0.51, 0.90) | 0.77 (0.56, 1.05) |
| Q3 (13.90–20.20) | 0.65 (0.50, 0.85) | 0.60 (0.46, 0.80) | 0.72 (0.54, 0.97) |
| Q4 (20.20–209.30) | 0.62 (0.47, 0.81) | 0.55 (0.40, 0.74) | 0.70 (0.51, 0.96) |
| p for trend | <0.001 | <0.001 | 0.021 |
Model 1: no covariates were adjusted. Model 2: age, gender, and race/ethnicity were adjusted. Model 3: age, gender, race/ethnicity, education level, marital status, alcohol use, smoking status, BMI, hypertension, and diabetes were adjusted.