eTable 2. Substance use prevalence estimates by survey mode, n (weighted %) *1.
| Written (n = 3696) | Telephone (n = 916) | Online(n = 4434) | |
| Alcohol use | |||
| 30-Day prevalence | 2636 (69.0) | 673 (70.6) | 3248 (71.7) |
| Episodic heavy drinking, preceding 30 days*2 | 913 (35.6) | 188 (26.9)*3 | 1138 (32.8)*4 |
| Tobacco use | |||
| 30-Day Prevalence | 761 (24.3) | 188 (24.7) | 767 (20.7)*4 |
| Average number of cigarettes per day, M (SD)*2 | 11.9 (11.2) | 11.4 (8.8) | 9.8 (8.3)*3 |
| Cannabis use | |||
| Lifetime prevalence | 1462 (37.3) | 221 (21.5)*4 | 1675 (35.4)*4 |
| 12-Month prevalence | 416 (9.4) | 56 (4.2)*3 | 532 (9.3)*3 |
| Medication use, preceding 12 months | |||
| Analgesics | 2777 (73.4) | 687 (73.1) | 3172 (69.6)*3 |
| Hypnotics | 233 (6.3) | 46 (4.9) | 219 (5.0) |
*1 Adjusted for age, sex, federal state, school education, and household income (control variables) with logistic or linear regression models
*2 In relation to 30-day users
*3 Statistically significant difference to “written” with p < 0.05
*4 Statistically significant difference to “written” with p < 0.01
M, mean; SD, standard deviation