Table 3.
Variability in Objective Sleep Measures and Odds of MCI or Dementia
| Outcome = MCI or Dementia vs. Normal |
||||
|---|---|---|---|---|
| Minimally Adjusteda | Multivariate Adjustedb | |||
| Predictor (SD over all nights) | OR (95% CI) | Wald χ2 [1, N=1242], p-value | OR (95% CI) | Wald χ2 [1, N=1220], p-value |
| Total Sleep Time, minutes | ||||
| Q1 (<28.58) | 1.00 (reference) | - - | 1.00 (reference) | - - |
| Q2 (28.58 to <42.16) | 0.81 (0.58-1.14) | 1.49, p = 0.22 | 0.82 (0.58-1.17) | 1.21, p = 0.27 |
| Q3 (42.16 to <61.04) | 0.96 (0.68-1.34) | 0.07, p = 0.79 | 0.98 (0.69-1.38) | 0.02, p = 0.89 |
| Q4 (≥61.04) | 1.36 (0.97-1.91) | 3.26, p = 0.07 | 1.40 (0.98-1.98) | 3.47, p = 0.06 |
| p-trend | 4.02, p = 0.045 | 4.05, p = 0.04 | ||
| Sleep Efficiency, % | ||||
| Q1 (<2.99) | 1.00 (reference) | - - | 1.00 (reference) | - - |
| Q2 (2.99 to <4.93) | 1.83 (1.30-2.57) | 12.00, p = 0.0005 | 1.89 (1.33-2.69) | 12.50, p = 0.0004 |
| Q3 (4.93 to <7.92) | 1.43 (1.01-2.02) | 4.11, p = 0.04 | 1.48 (1.04-2.12) | 4.60, p = 0.03 |
| Q4 (≥7.92) | 1.87 (1.32-2.64) | 12.65, p = 0.0004 | 1.92 (1.34-2.75) | 12.74, p = 0.0004 |
| p-trend | 8.40, p = 0.004 | 8.66, p = 0.003 | ||
| Wake After Sleep Onset, minutes | ||||
| Q1 (<11.64) | 1.00 (reference) | - - | 1.00 (reference) | - - |
| Q2 (11.64 to <20.33) | 1.31 (0.94-1.83) | 2.52, p = 0.11 | 1.29 (0.91-1.82) | 2.10, p = 0.15 |
| Q3 (20.33 to <37.44) | 1.21 (0.86-1.69) | 1.17, p = 0.28 | 1.22 (0.86-1.73) | 1.26, p = 0.26 |
| Q4 (≥37.44) | 1.24 (0.88-1.75) | 1.54, p = 0.21 | 1.25 (0.87-1.78) | 1.48, p = 0.22 |
| p-trend | 1.04, p = 0.31 | 1.11, p = 0.29 | ||
| Sleep Latency, minutes | ||||
| Q1 (<10.10) | 1.00 (reference) | - - | 1.00 (reference) | - - |
| Q2 (10.10 to <18.15) | 1.00 (0.71-1.40) | 0.00, p = 1.00 | 0.98 (0.69-1.38) | 0.02, p = 0.90 |
| Q3 (18.15 to <33.89) | 0.94 (0.67-1.32) | 0.11, p = 0.74 | 0.92 (0.65-1.31) | 0.20, p = 0.66 |
| Q4 (≥33.89) | 1.36 (0.98-1.91) | 3.30, p = 0.07 | 1.37 (0.97-1.94) | 3.20, p = 0.07 |
| p-trend | 2.66, p = 0.10 | 2.60, p = 0.11 | ||
a
Adjusted for age, race, clinic and education
b
Adjusted for age, race, clinic, education, body mass index, number of depressive symptoms, comorbidities, number of IADL impairments, smoking status, alcohol use, exercise, living alone, self-reported health status, antidepressant use, benzodiazepine use, and prescription sleep medication use.
A separate model was run for each predictor.