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. 2016 Jun 28;77(4):649–655. doi: 10.15288/jsad.2016.77.649

Table 1.

Results from Cox proportional hazards models

graphic file with name jsad.2016.77.649tbl1.jpg

Activity-Sleep
Rhythmicity-Sleep
Variable HR [95% CI] Wald χ2 P HR [95% CI] Wald χ2 P
Alcohol
 Ever tried 1.11 [1.02, 1.21] 5.84 .016 0.95 [0.87, 1.03] 1.56 .21
 Disorder 1.03 [0.89, 1.19] 0.15 .69 0.82 [0.71, 0.95] 6.67 .01
Cannabis
 Ever tried 1.13 [1.02, 1.24] 5.31 .021 0.96 [0.87, 1.06] 0.71 .39
 Disorder 1.15 [0.98, 1.34] 3.08 .079 0.88 [0.75, 1.02] 2.76 .097
Cocaine
 Ever tried 1.09 [0.86, 1.40] 0.51 .48 0.95 [0.74, 1.22] 0.19 .66
 Disorder 0.97 [0.70, 1.35] 0.03 .86 0.72 [0.51, 1.01] 3.71 .054
Depressive
 Disorder 1 .23 [1.06, 1.42] 7.43 .006 0.96 [0.83, 1.11] 0.32 .57

Notes: HR = hazard ratio; CI = confidence interval. All models included sex, age at Visit 1, race, and the presence of parental substance use disorder as covariates. We also explored interactions between the sleep predictors and other covariates, but no interactions were statistically significant.