Table 1.
Sample characteristics
| M (SD) or % | |||||
|---|---|---|---|---|---|
| Variable | Total sample (n=341) | Any daily co-use sample (n=284) | No daily co-use sample (n=57) | χ2 or t | p |
| Sex (female) | 51.3% | 50.7% | 54.4% | 0.131 | .717 |
| White | 74.8% | 75.4% | 71.9% | 0.141 | .707 |
| Hispanic | 10.0% | 8.8% | 15.8% | 1.86 | .172 |
| Age | 19.8 (1.32) | 19.8 (1.35) | 19.4 (1.10) | 2.40 | .018 |
| AUDIT | 9.71 (5.21) | 9.92 (5.32) | 8.72 (4.57) | 1.75 | .084 |
| CUDIT-R | 9.55 (6.10) | 10.20 (6.05) | 6.44 (5.39) | 4.68 | <.001 |
| Drinks per drinking day | 4.87 (2.67) | 5.06 (2.50) | 3.92 (3.21) | 2.57 | .012 |
| Marijuana uses per use day | 3.61 (3.32) | 3.96 (3.40) | 1.91 (2.22) | 5.76 | <.001 |
| Proportion plant-only days | 70.5% | 70.2% | 72.6% | 0.385 | .702 |
| Proportion nicotine use days | 23.0% | 24.9% | 13.9% | 2.70 | .008 |
| Proportion other drug use days | 3.4% | 3.8% | 1.9% | 2.31 | .023 |
Note: Proportion of plant-only use days, nicotine use days, and other drug use days were aggregated at the subject level (i.e., mean of subject-level proportions of use days) rather than the day level (i.e., proportion of days across all participants) for the sake of presentation in this Table but not in the analyses. Denominator for proportion of plant-only days is marijuana use days. Denominator for nicotine use days and other drug use days is total study days. AUDIT=Alcohol Use Disorders Identification Test; CUDIT-R=Cannabis use Disorder Identification Test Revised. χ2 or t difference tests reflect differences between the subset of participants with any daily co-use (n=284) and those in the final sample but no reports of daily co-use (n=57). Absolute vaue of t-tests is presented.