Pilot 1 (N = 1000) | Pilot 2 (N = 2000) | % difference | 95% CI for % difference | p-value | |||
---|---|---|---|---|---|---|---|
n^ | % | n^ | % | ||||
After initial mail out (Before reminder 1 mail out) | 169 | 16.9 | 371 | 18.6 | +1.7 | -1.25, 4.52 | 0.25 |
After reminder 1 mail out (Before reminder 2 mail out) | 276 | 27.6 | 564 | 28.2 | +0.6 | -2.84, 3.95 | 0.73 |
End of survey (After reminder 2 mail out in pilot 2 only) | 287 | 28.7 | 662 | 33.1 | +4.4 | 0.88, 7.83 | 0.02* |
Postal (end of survey) | 268 | 26.8 | 593 | 29.7 | +2.9 | −0.54, 6.25 | 0.10 |
Online (end of survey) | 18 | 1.8 | 69 | 3.5 | +1.7 | 0.45, 2.81 | 0.01* |
Telephone (end of survey) | 1 | 0.1 | 0 | 0 | −0.1 | −0.11, 0.56 | 0.16 |