Table 2 Outcomes
Outcome | First mailout (n = 503) | Reminder (n = 515) | Effect measure (95 % CI) | ||
|---|---|---|---|---|---|
n | % | n | % | ||
Primary outcome | |||||
Questionnaire returned Postal Online | 373 306 67 | (74.2) (82.0) (18.0) | 370 285 85 | (71.8) (77.0) (23.0) | RRa 1.03 (0.96 to 1.11) |
Secondary outcomes | |||||
Questionnaire returned without chasing by study team Postal Online | 259 207 52 | (51.5) (79.9) (20.1) | 217 161 56 | (42.1) (74.2) (25.8) | RRa 1.22 (1.07 to 1.39) |
Total cost of vouchers, £ | 3790 | 1530 | MD 4.56 (4.02 to 5.11) | ||
Cost of vouchers per participant, £ – mean {SD} | 7.53 | {4.31} | 2.97 | {4.57} | |