TABLE 5.
Descriptive statistics for participants with baseline data only vs. baseline and longitudinal data.
| Participant characteristics | Participants with baseline data only (N = 130) | Participants with baseline + longitudinal data (N = 292) | Chi-squared | t-value | P-value |
| Baseline Age, in years, M ± SD | 69.2 ± 11.7 | 75.9 ± 8.83 | – | −4.45 | 0.00001 |
| Sex, N (%) | 0.98 | – | 0.321 | ||
| Male | 66 (49.2%) | 133 (33.9%) | – | – | – |
| Female | 64 (50.8%) | 159 (54.5%) | – | – | – |
| Race | 1.09 | – | 0.580 | ||
| White | 96 (73.8%) | 212 (70.5%) | – | – | – |
| Black | 28 (21.5%) | 69 (22.2%) | – | – | – |
| Other | 6 (4.6%) | 23 (7.2%) | – | – | – |
| Baseline educational attainment (in years), M ± SD | 17.5 ± 2.20 | 17.8 ± 2.52 | – | −1.58 | 0.115 |
| Baseline BMI, M ± SD | 27.5 ± 4.62 | 26.6 ± 4.04 | – | 1.47 | 0.144 |
| Baseline CES-D Score,a M ± SD | 3.91 ± 4.50 | 3.72 ± 4.26 | – | 0.35 | 0.730 |
| Baseline use of sleep medication,b N (%) | 0.18 | – | 0.671 | ||
| No | 105 (84.0%) | 250 (85.6%) | – | – | – |
| Yes | 20 (16.0%) | 42 (14.4%) | – | – | – |
| Baseline cardiovascular disease risk factors/morbidity, N (%) | 6.70 | – | 0.010 | ||
| No | 72 (55.0%) | 122 (41.8%) | – | – | – |
| Yes | 59 (45.0%) | 170 (58.2%) | – | – | – |
| Baseline smoking status,b,c N (%) | – | – | 0.392 | ||
| Never smoked or quit > 10 years ago | 122 (95.3%) | 285 (98.3%) | – | – | – |
| Current smoker or quit < 10 years ago | 6 (4.7%) | 5 (1.7%) | – | – | – |
| APOE Carrier Status,b n (%) | 0.34 | – | 0.562 | ||
| APOE e4− | 85 (75.5%) | 206 (73.0%) | – | – | – |
| APOE e4+ | 27 (22.5%) | 76 (27.0%) | – | – | – |
| Baseline CRARs, M ± SD | |||||
| Amplitude | 2.18 ± 0.38 | 2.13 ± 0.40 | – | 0.81 | 0.420 |
| Mesor | 3.22 ± 0.39 | 3.22 ± 0.40 | – | −0.46 | 0.648 |
| Acrophase | 14.8 ± 1.04 | 14.7 ± 1.17 | – | 1.21 | 0.228 |
| Relative amplitude | 0.78 ± 0.08 | 0.77 ± 0.65 | – | 1.47 | 0.143 |
| Intradaily stability | 0.11 ± 0.32 | 0.11 ± 0.33 | – | 0.19 | 0.849 |
| Interdaily variability | 0.32 ± 0.10 | 0.33 ± 0.11 | – | −0.41 | 0.684 |
| L5 time | 1.54 ± 1.20 | 1.51 ± 1.37 | – | 0.11 | 0.917 |
| M10 time | 9.26 ± 1.28 | 8.97 ± 1.45 | – | 1.81 | 0.071 |
| Cognitive outcomes, M ± SD | |||||
| Verbal memory | 0.11 ± 1.01 | −0.08 ± 0.97 | – | 1.61 | 0.109 |
| Executive function | 0.12 ± 0.89 | −0.19 ± 0.72 | – | 2.17 | 0.031 |
| Attention | 0.13 ± 0.96 | −0.16 ± 0.77 | – | 1.95 | 0.053 |
| Language | 0.11 ± 0.98 | −0.11 ± 0.77 | – | 1.56 | 0.120 |
| Visuospatial skills | 0.22 ± 0.86 | −0.13 ± 0.77 | – | 3.19 | 0.002 |
aCES-D, Center for Epidemiologic Studies Depression Scale score without the sleep item.
bPercentages based on participants with complete data.
cFisher’s test was used to determine differences in smoking status between those with baseline data only vs. longitudinal data. M, mean; SD, standard deviation.