Table 1.
Characteristics of subjects by participating study centers and analysis of compliance and time for completion
| Bremen n = 87 | Hamburg n = 90 | Heidelberg n = 105 | Freiburg n = 156 | |
|---|---|---|---|---|
| Women (%) | 57 | 57 | 46 | 51 |
| Mean age + SD (years) | 49.6 ± 13.6 | 46.8 ± 15.6 | 44.1 ± 14.9 | 48.9 ± 13.4 |
| Migration backgrounda (%) | 33.3 | 30.8 | 37.7 | 26.3 |
| Questionnaire | Take home | Take home | Study center | Study center |
| Participation ID Screen (%) | 87 | 90 | 95 | 99 |
| Median time to complete (min) | 10 | 10 | 6 | 8 |
| [Inter quartile range] | [6–17] | [6–14.5] | [5–8] | [5–10] |
| Missing responses per questionnaire (mean) | 2.0/33 | 0.7/33 | 0.5/33 | 0.6/33 |
| CI95 % | 1.5–2.5 | 1.0–1.4 | 0.8–1.1 | 0.8–1.1 |
| Min–max | 0–18 | 0–12 | 0–9 | 0–9 |
| Incomplete questionnaires (> 16/33 missing values) | 1 | – | – | – |
| Subjects receiving help from study nurse (n) | Not applicable | Not applicable | 1 | 4 |
aMigrations status was determined according to Schenk et al. [12]