Meningioma cases | Glioma cases | Controls | |
Eligible | 321 | 494 | 955 |
Participants (% participation) | 274 (85) | 366 (74) | 673 (70) |
Personal interview | 259 | 346 | 592 |
Telephone interview | 12 | 18 | 40 |
Written questionnaire | 3 | 2 | 41 |
Non-participants | 47 | 128 | 282 |
Refusals | 21 | 27 | 167 |
Failure of contact | 4 | 11 | 101 |
No permission to contact* | 7 | 31 | |
Too sick or deceased† | 15 | 59 | 14 |