Table 3.
Variability in Objective Sleep Measures and Odds of MCI or Dementia
Outcome = MCI or Dementia vs. Normal |
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---|---|---|---|---|
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 |
Adjusted for age, race, clinic and education
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.