eTable 3. A comparison of variables of use according to willingness to participate, n (%)*1.
| Participants | Non-participants*2 | |
| n = 9267 | n = 1204 | |
| Alcohol use | ||
| 30-Day prevalence | 6859 (74.2) | 786 (66.3)*4 |
| Episodic heavy drinking in the preceding 30 days*3 | 2488 (36.6) | 445 (60.4)*4 |
| Tobacco use | ||
| 30-Day prevalence | 1870 (20.2) | 256 (21.7) |
| Average number of cigarettes per day, M (SD)*3 | 9.5 (9.1) | 10.1 (8.5) |
| Cannabis use | ||
| Lifetime prevalence | 2850 (30.8) | 232 (19.4)*4 |
| 12-Month prevalence | 909 (9.8) | 72 (6.0)*4 |
| Medication use in the preceding 12 months | ||
| Analgesics | 6341 (69.0) | 782 (65.5)*5 |
| Hypnotics | 441 (4.8) | 75 (6.3)*5 |
*1Logistic and linear regression model adjusted according to age, sex, federal state, and interview type;
*2individuals that completed the “non-response” questionnaire (12.7% of all non-responders);
*3in relation to 30-day consumers; *4p <0.01 for comparison with “participants”; *5p <0.05 for comparison with “participants”