Table 3.
Sleep efficiency mixed-effects beta model results.
| 95% CI for OR | ||||||
|---|---|---|---|---|---|---|
| Coefficient | SE | OR | Lower | Upper | P Value | |
| COPD vs no COPD | −.25 | .11 | .78 | .62 | .97 | .024 |
| Linear time (0 = baseline) | −.03 | .03 | .97 | .92 | 1.03 | .347 |
| Age | .01 | .00 | 1.01 | 1.00 | 1.02 | .009 |
| Male vs female | .21 | .10 | 1.23 | 1.01 | 1.49 | .037 |
| Race | ||||||
| White vs other | .30 | .28 | 1.35 | .78 | 2.33 | .282 |
| Black vs other | .23 | .27 | 1.26 | .75 | 2.12 | .390 |
| White vs Black | .07 | .12 | 1.07 | .85 | 1.35 | .552 |
| BMI | .00 | .00 | 1.00 | 1.00 | 1.01 | .473 |
| Prior hospitalization | .09 | .11 | 1.10 | .88 | 1.36 | .405 |
| CHF | −.05 | .14 | .95 | .72 | 1.26 | .742 |
| ESRD | .17 | .16 | 1.19 | .86 | 1.64 | .291 |
| Diabetes | −.02 | .11 | .98 | .79 | 1.22 | 0.881 |
| Intercept | −.17 | .36 | — | — | — | — |
COPD = chronic obstructive pulmonary disease. BMI = body mass index. CHF = congestive heart failure, CI, confidence interval, ESRD = end stage renal disease, OR, odds ratio, SE, standard error.
Random intercept variance = 0.44, SE = 0.07. Scale = 6.84, SE = 0.62. Sleep efficiency was modeled as a proportion with 0 = no sleep efficiency and 1 = perfect sleep efficiency. In a beta model, we are predicting the probability of the outcome coded 1 (ie, perfect sleep efficiency); fixed effects are interpreted similarly to logistic regression. The reference category for the fixed effect for any categorical predictor is identified following the “vs” For example, the odds of reporting normal sleep efficiency were 22% lower for patients with a COPD diagnosis relative to those with no COPD diagnosis (ie, [1–0.78]*100).