Table 1.
Group differences between current good and poor sleep quality groups
| PSQI < 6 | PSQI ≥ 6 | Cohen's d | P | |
|---|---|---|---|---|
| Demographics | ||||
| N (%) | 301 (67%) | 147 (33%) | ||
| Age (years) | 69.0 ± 5.0 | 69.4 ± 5.5 | 0.07 | 0.255 |
| Sex (N females, %) | 49 (16%) | 41 (28%) | 0.004 | |
| Education level | 3.5 ± 1.0 | 3.4 ± 1.1 | −0.12 | 0.123 |
| Health and Lifestyle | ||||
| BMI | 25.9 ± 4.1 | 26.6 ± 4.2 | 0.16 | 0.056 |
| Blood pressure (MAP) | 96.9 ± 11.5 | 98.1 ± 11.2 | 0.13 | 0.101 |
| Depressive symptoms (CES‐D, excluding sleep item) | 3.3 ± 4.8 | 6.4 ± 6.7 | 0.57 | <0.001 |
| Psychotropic medication (N) | 8 (3%) | 8 (5%) | 0.107 | |
| Physical activity (MET.Minutes) | 1621.0 ± 1386.2 | 1596.8 ± 1663.6 | −0.02 | 0.578 |
| General cognition | ||||
| MoCA | 27.3 ± 2.2 | 27.1 ± 2.4 | 0.11 | 0.141 |
| Executive function | ||||
| Digit span forward | 11.2 ± 2.2 | 10.9 ± 2.3 | −0.09 | 0.191 |
| Digit span backward | 9.9 ± 2.6 | 9.8 ± 2.6 | <0.01 | 0.495 |
| Digit span sequence | 10.3 ± 2.4 | 10.1 ± 2.6 | −0.03 | 0.400 |
| Fluency: Category | 22.7 ± 5.5 | 21.7 ± 5.6 | −0.15 | 0.070 |
| Fluency: Letter | 15.9 ± 4.6 | 15.6 ± 4.4 | −0.04 | 0.344 |
| Trail Making Test: Ba | −65.0 ± 32.6 | −68.4 ± 39.2 | −0.04 | 0.348 |
| Memory | ||||
| HVLT‐R: Total recall | 28.0 ± 4.3 | 28.0 ± 5.0 | 0.01 | 0.461 |
| HVLT‐R: Delayed recall | 9.4 ± 2.5 | 9.5 ± 2.7 | 0.02 | 0.405 |
| HVLT‐R: Recognition | 10.8 ± 1.4 | 10.8 ± 1.4 | −0.03 | 0.369 |
| RCF: Immediate recall | 15.9 ± 6.5 | 15.4 ± 6.7 | −0.02 | 0.405 |
| RCF: Delayed recall | 15.6 ± 6.1 | 15.1 ± 6.3 | −0.02 | 0.422 |
| RCF: Recognition | 8.5 ± 1.9 | 8.6 ± 2.0 | 0.10 | 0.169 |
| Processing Speed | ||||
| Trail making test: Aa | −29.6 ± 11.2 | −30.3 ± 9.1 | −0.02 | 0.432 |
| Digit coding | 63.4 ± 13.2 | 61.8 ± 12.8 | −0.11 | 0.141 |
| Simple: Reaction timea | −292.5 ± 63.8 | −302.6 ± 68.3 | −0.11 | 0.138 |
| Choice: Reaction timea | −327.8 ± 43.8 | −337.4 ± 55.5 | −0.17 | 0.051 |
| Simple: Movement timea | −264.3 ± 87.0 | −275.3 ± 83.1 | −0.06 | 0.262 |
| Choice: Movement timea | −283.0 ± 74.9 | −290.1 ± 81.9 | −0.04 | 0.345 |
| Global white matter | ||||
| WMH (%)b | 0.405 ± 0.267 | 0.426 ± 0.309 | 0.01 | 0.442 |
| FA | 0.478 ± 0.017 | 0.474 ± 0.019 | ‐0.18 | 0.037 |
| AD (x103) | 1.070 ± 0.023 | 1.076 ± 0.023 | 0.18 | 0.041 |
| RD (x103) | 0.482 ± 0.025 | 0.489 ± 0.028 | 0.19 | 0.034 |
a
Reverse scored so that higher scores indicate better performance.
b
N = 443.
Values are mean ± standard deviation.
Age, sex, and education were included as covariates in all analyses, except those of demographics. Education was scored on a five‐point scale: (1) no qualifications, (2) O‐levels or equivalent, (3) A‐levels, college certificate or professional qualification, (4) degree, (5) higher degree.