Table 1.
Participation and reasons for non-participation in ISAAC Phase Two, SOLAR I and SOLAR II
| Total | Munich | Dresden | |
|---|---|---|---|
| n (%) | n (%) | n (%) | |
|
ISAAC Phase Two Questionnaire study |
6399 (85.3)1 | 3354 (87.6) | 3045 (83.0) |
| SOLAR I | 3785 (77.4)2 | 2043 (81.5) | 1742 (73.0) |
| of these: | |||
| Agreed to be re-contacted | 3053 (80.7) | 1534 (75.1) | 1519 (87.2) |
| SOLAR II | |||
| Drop-outs in total | 149 (4.9) | 85 (5.5) | 64 (4.2) |
| Address could not be found via population registries | 143 (4.7) | 82 (5.3) | 61 (4.0) |
| Deceased | 6 (0.2) | 3 (0.2) | 3 (0.2) |
| Eligible study population | 2904 (100.0) | 1449 (100.0) | 1455 (100.0) |
| Refusals in total | 853 (29.4) | 441 (30.4) | 412 (28.3) |
| of these | |||
| Could not be reached by phone/no phone number available | 454 (53.3) | 184 (41.7) | 270 (65.5) |
| Lack of interest/time | 262 (30.7) | 146 (33.0) | 116 (28.2) |
| Absence from study location during the entire field phase | 59 (6.9) | 41 (9.3) | 18 (4.4) |
| Other reasons | 78 (9.1) | 70 (15.8) | 8 (1.9) |
| Response: questionnaire part | 2051 (70.6) | 1008 (69.6) | 1043 (71.1) |
| Response: clinical study | 1167 (40.2) | 568 (39.2) | 599 (41.2) |
1 6399 of 7498 invited children
2 3785 of 4893 invited adolescents who could be re-contacted