Table 1.
Response and participation rate in the Nightingale Study
| N (%) | |
|---|---|
|
Eligible and invited |
192,931 |
| Response received (responders) |
76,932 (40%) |
| No response received |
115,039 (60%) |
| Lost to follow-up (mail returned undeliverable) |
960 (<1%) |
|
Responders |
|
| Declined participation |
3,526 (2%) |
| Questionnaire completeda (participants) |
59,947 (31%)b |
| Incomplete questionnairec |
13,459 (7%) |
|
Participants |
|
| Questionnaire only |
36,508 (61%) |
| Questionnaire and toenail sample | 23,439 (39%) |
a Includes 4,889 women who filled in at least half of the questionnaire (i.e. the most important part on occupational and other risk factors) but did not complete the entire questionnaire.
b Includes 179 women who participated through the self-registration system.
c Women who did completed less than half of the questionnaire.