Table 2.
Fixed Effects of Associations between Sleep Parameters and Global Cognition
| Predictors | Coefficient (SE) | p |
|---|---|---|
| Model 1 | ||
| Time | −0.02 (0.02) | 0.28 |
| Age | −0.02 (0.00) | <0.001 |
| Age*time | −0.00 (0.00) | <0.01 |
| Female | 0.05 (0.03) | 0.12 |
| Female*time | −0.02 (0.01) | 0.15 |
| Married | 0.05 (0.03) | 0.11 |
| Married*time | 0.02 (0.02) | 0.13 |
| Education | 0.08 (0.00) | <0.001 |
| Education*time | −0.00 (0.00) | <0.05 |
| Income | 0.01 (0.01) | 0.54 |
| Income*time | −0.00 (0.01) | 0.83 |
| Acculturation | 0.02 (0.00) | <0.001 |
| Acculturation*time | 0.00 (0.00) | 0.61 |
| Years in the US | 0.00 (0.00) | 0.60 |
| Years in the US*time | 0.00 (0.00) | 0.23 |
| Physical activity | −0.03 (0.00) | <0.001 |
| Physical activity*time | 0.00 (0.00) | 0.52 |
| Alcohol use | −0.03 (0.20) | 0.90 |
| Alcohol use*time | 0.09 (0.10) | 0.37 |
| BMI | ||
| Normal (ref) | ||
| Overweight | 0.08 (0.03) | <0.01 |
| Obese | −0.03 (0.07) | 0.65 |
| BMI*time | ||
| Normal (ref) | ||
| Overweight | −0.00 (0.02) | 0.97 |
| Obese | 0.04 (0.03) | 0.28 |
| Depression | −0.01 (0.01) | 0.09 |
| Depression*time | 0.00 (0.00) | 0.12 |
| IADL | −0.03 (0.00) | <0.001 |
| IADL*time | 0.00 (0.00) | 0.66 |
| Daytime sleepinessa | ||
| Never (ref) | ||
| Rarely | −0.04 (0.04) | 0.34 |
| Sometimes | −0.09 (0.04) | <0.05 |
| Often | −0.08 (0.05) | 0.08 |
| Almost always | 0.13 (0.06) | <0.05 |
| Daytime sleepiness*timea | ||
| Never (ref) | ||
| Rarely | 0.01 (0.02) | 0.75 |
| Sometimes | −0.01 (0.02) | 0.55 |
| Often | 0.04 (0.02) | 0.09 |
| Almost always | −0.03 (0.03) | 0.27 |
| PSQI | −0.01 (0.01) | <0.01 |
| PSQI*time | 0.01 (0.00) | <0.05 |
| Model 2 | ||
| Insomnia | −0.01 (0.00) | <0.001 |
| Insomnia*time | 0.00 (0.00) | <0.05 |
| Model 3 | ||
| Subjective sleep quality | ||
| Very good (ref) | ||
| Fairly good | −0.04 (0.04) | 0.35 |
| Fairly bad | −0.04 (0.05) | 0.42 |
| Very bad | −0.28 (0.06) | <0.001 |
| Subjective sleep quality*time | ||
| Very good (ref) | ||
| Fairly Good | 0.06 (0.02) | <0.01 |
| Fairly Bad | 0.05 (0.02) | <0.05 |
| Very Bad | 0.09 (0.03) | <0.01 |
| Model 4 | ||
| Sleep latency | ||
| <=15 min (ref) | ||
| 15–30 min | 0.05 (0.03) | 0.09 |
| 30–60 min | −0.13 (0.04) | <0.01 |
| >60 min | −0.08 (0.05) | 0.09 |
| Sleep latency*time | ||
| <=15 min (ref) | ||
| 15–30 min | 0.01 (0.02) | 0.74 |
| 30–60 min | 0.02 (0.02) | 0.31 |
| >60 min | −0.00 (0.02) | 0.97 |
| Model 5 | ||
| Sleep efficiency | ||
| >=85% (ref) | ||
| 75–85% | 0.05 (0.04) | 0.16 |
| 65–75% | 0.05 (0.05) | 0.32 |
| <65% | −0.08 (0.04) | 0.06 |
| Sleep efficiency*time | ||
| >=85% (ref) | ||
| 75–85% | 0.00 (0.02) | 0.99 |
| 65–75% | 0.01 (0.02) | 0.60 |
| < 65% | 0.02 (0.02) | 0.30 |
| Model 6 | ||
| Sleep duration | ||
| >=7h (ref) | ||
| 6–7h | 0.07 (0.03) | <0.05 |
| 5–6h | −0.02 (0.04) | 0.62 |
| <5h | −0.09 (0.04) | <0.05 |
| Sleep duration*time | ||
| >=7h (ref) | ||
| 6–7h | 0.03 (0.02) | 0.07 |
| 5–6h | 0.04 (0.02) | <0.05 |
| <5h | 0.04 (0.02) | 0.07 |
Note. Model 2 controlled for all covariates except daytime sleepiness and the interaction between daytime sleepiness and time, considering daytime sleepiness as one item measuring insomnia. Models 3 to 6 controlled for all covariates as those in Model 1.