Table 5.
Sleep Predicting Future Functional Impairment During Recovery
| b | 95% CI | z | p | χ2, p | |
|---|---|---|---|---|---|
| Model 1: Sleep predicting future global functioning during recovery (n = 156, obs = 247) | |||||
| Baseline factors | 72.01, <.001 | ||||
| Female gender | −.36 | −.62, −.09 | −2.65 | <.01 | |
| Head injury severity | −.22 | −.35, −.09 | −3.41 | <.01 | |
| Loss of consciousness | −.19 | −.44, .06 | −1.48 | .14 | |
| Recovery factors | |||||
| Time | .12 | −.03, .26 | 1.56 | .12 | |
| Depression, lagged | −.03 | −.05, −.01 | −3.13 | <.01 | |
| Sleep disturbance, lagged | −.04 | −.06, −.01 | −2.56 | .01 | |
| Model 2: Logistic model of sleep predicting future functional impairment (n = 126, obs = 214) | |||||
| Baseline factors | OR; 95% CI | 16.04, .02 | |||
| Female gender | −1.69 | 5.26; .83, 33.33 | −1.76 | .08 | |
| Head injury severity | −.92 | 2.50; 1.02, 6.25 | −2.00 | <.05 | |
| Loss of consciousness | −1.54 | 4.76; .79, 25.00 | −1.70 | .09 | |
| Recovery factors | |||||
| Time | .49 | — | .91 | .36 | |
| Depression, lagged | −.99 | — | −1.28 | .20 | |
| Sleep onset insomnia, lagged | −1.96 | 7.14; 1.56, 33.33 | −2.54 | .01 | |
| Short sleep, lagged | −.87 | — | −1.18 | .24 | |
| Model 3: Global functioning predicting future sleep (n = 154, obs = 246) | |||||
| Baseline factors | 85.72, <.001 | ||||
| Female gender | 2.66 | 1.43, 3.89 | 4.26 | <.001 | |
| Head injury severity | −.23 | −.84, .39 | −.72 | .47 | |
| Loss of consciousness | .70 | −.49, 1.88 | 1.16 | .25 | |
| Recovery factors | |||||
| Time | .09 | −.70, .88 | .22 | .82 | |
| Depression, lagged | .19 | .08, .29 | 3.53 | <.001 | |
| Functional impairment, lagged | −.86 | −1.48, −.24 | −2.73 | <.01 | |
Global functioning assessed by the GOSE. Functional impairment defined as GOSE ≤ 6. TBI severity assessed by the Glasgow Coma Scale. Head injury severity measured by the AIS, item #1. Loss of consciousness at time of injury was self-reported by patient. Depression measured by the PHQ. Sleep disturbance measured by the PSQI. Sleep latency was estimated in minutes on the PSQI, item #2. Sleep duration was measured by PSQI item #4a. Sleep onset insomnia = rating inability to fall asleep within 30 minutes on three or more nights per week, PSQI item #5a. n = sample size; b = unstandardized regression coefficient; CI = confidence interval; z = z-statistic; p = significance value, which describes whether the model explains greater variance in the outcome than a null model with no predictors. obs = number of observations in model. OR (values are inversed for negative associations to ease interpretability), not reported for parameters with p-values > .10.