Table 3 Recruitment, retention and attrition rates by study centre and treatment arm
Nott | Bris | New | Nor | Total | Nott | Bris | New | Nor | Total | Nott | Bris | New | Nor | Total | Nott | Bris | New | Nor | Total | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
IPB+ | IPB only | Control | Total | |||||||||||||||||
Baseline* | ||||||||||||||||||||
Parents approached | 92 | 128 | 94 | 104 | 418 | 101 | 135 | 93 | 101 | 430 | 90 | 115 | 94 | 118 | 417 | 283 | 378 | 281 | 323 | 1,265 |
Passive refusal | 0 | 20 | 2 | 10 | 32 | 0 | 34 | 2 | 15 | 51 | 0 | 12 | 2 | 22 | 36 | 0 | 66 | 6 | 47 | 119 |
Passive refusal rate | 0% | 16% | 2% | 10% | 8% | 0% | 25% | 2% | 15% | 12% | 0% | 10% | 2% | 19% | 9% | 0% | 17% | 2% | 15% | 9% |
Active refusal | 0 | 2 | 3 | 1 | 6 | 0 | 1 | 3 | 2 | 6 | 0 | 2 | 4 | 1 | 7 | 0 | 5 | 10 | 4 | 19 |
Active refusal rate | 0% | 2% | 3% | 1% | 1% | 0% | 1% | 3% | 2% | 1% | 0% | 2% | 4% | 1% | 2% | 0% | 1% | 4% | 1% | 2% |
Total refusals | 0 | 22 | 5 | 11 | 38 | 0 | 35 | 5 | 17 | 57 | 0 | 14 | 6 | 23 | 43 | 0 | 71 | 16 | 51 | 138 |
Total refusal rate | 0% | 17% | 5% | 11% | 9% | 0% | 26% | 5% | 17% | 13% | 0% | 12% | 6% | 20% | 10% | 0% | 19% | 6% | 16% | 11% |
Incomplete consent form | 1 | 1 | 0 | 0 | 2 | 0 | 0 | 0 | 1 | 1 | 1 | 0 | 0 | 0 | 1 | 2 | 1 | 0 | 1 | 4 |
Incomplete consent rate | 1% | 1% | 0% | 0% | 0% | 0% | 0% | 0% | 1% | 0% | 0% | 0% | 0% | 0% | 0% | 1% | 0% | 0% | 0% | 0% |
Excluded/ ineligible | 0 | 2 | 2 | 0 | 4 | 3 | 0 | 0 | 1 | 4 | 0 | 1 | 2 | 0 | 3 | 3 | 3 | 4 | 1 | 11 |
Excluded rate | 0% | 2% | 2% | 0% | 1% | 3% | 0% | 0% | 1% | 1% | 0% | 0% | 2% | 0% | 1% | 1% | 1% | 1% | 0% | 1% |
Not recruited | 1 | 25 | 7 | 11 | 44 | 3 | 35 | 5 | 19 | 62 | 1 | 15 | 8 | 23 | 47 | 5 | 75 | 20 | 53 | 153 |
Not recruited rate | 1% | 20% | 8% | 11% | 11% | 3% | 26% | 5% | 19% | 14% | 0% | 13% | 9% | 20% | 11% | 2% | 20% | 7% | 16% | 12% |
Participants randomised | 91 | 102 | 87 | 93 | 373 | 98 | 100 | 89 | 82 | 369 | 89 | 100 | 86 | 95 | 370 | 278 | 303 | 261 | 270 | 1,112 |
Recruitment rate | 99% | 80% | 93% | 89% | 89% | 97% | 74% | 96% | 81% | 86% | 99% | 87% | 91% | 81% | 89% | 98% | 80% | 93% | 84% | 88% |
12-month follow-up** | ||||||||||||||||||||
Parents approached | 89 | 96 | 75 | 92 | 352 | 95 | 97 | 78 | 79 | 349 | 87 | 97 | 80 | 95 | 359 | 271 | 290 | 233 | 269 | 1,060 |
Parents retained | 59 | 68 | 56 | 58 | 241 | 59 | 74 | 55 | 64 | 252 | 61 | 69 | 50 | 78 | 258 | 179 | 211 | 161 | 200 | 751 |
Retention rate (% of those recruited) | 65% | 67% | 64% | 62% | 65% | 60% | 74% | 62% | 78% | 68% | 69% | 69% | 58% | 82% | 70% | 64% | 70% | 62% | 74% | 68% |
Not approached | 2 | 6 | 12 | 1 | 21 | 3 | 3 | 11 | 3 | 20 | 2 | 3 | 6 | 0 | 11 | 7 | 12 | 29 | 4 | 52 |
Not approached rate (% of those recruited) | 2% | 6% | 14% | 1% | 6% | 3% | 3% | 12% | 4% | 5% | 2% | 3% | 7% | 0% | 3% | 3% | 4% | 11% | 1% | 5% |
Passive refusal | 30 | 24 | 19 | 31 | 104 | 36 | 22 | 22 | 15 | 95 | 25 | 26 | 29 | 16 | 96 | 91 | 72 | 70 | 62 | 295 |
Passive refusal rate | 34% | 25% | 25% | 34% | 30% | 38% | 23% | 28% | 19% | 27% | 29% | 27% | 36% | 17% | 27% | 34% | 25% | 30% | 23% | 28% |
Active refusal | 0 | 4 | 0 | 2 | 6 | 0 | 1 | 1 | 0 | 2 | 1 | 2 | 1 | 1 | 5 | 1 | 7 | 2 | 3 | 13 |
Active refusal rate | 0% | 4% | 0% | 2% | 2% | 0% | 1% | 1% | 0% | 1% | 1% | 2% | 1% | 1% | 1% | 0% | 2% | 1% | 1% | 1% |
Total refusals | 30 | 28 | 19 | 33 | 110 | 36 | 23 | 23 | 15 | 97 | 26 | 28 | 30 | 17 | 101 | 92 | 79 | 72 | 65 | 308 |
Total refusal rate | 34% | 29% | 25% | 36% | 31% | 38% | 24% | 29% | 19% | 28% | 30% | 29% | 38% | 18% | 28% | 34% | 27% | 31% | 24% | 29% |
Questionnaire lost | 0 | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 |
Total loss to follow-up | 32 | 34 | 31 | 35 | 132 | 39 | 26 | 34 | 18 | 117 | 28 | 31 | 36 | 17 | 112 | 99 | 91 | 101 | 70 | 361 |
Attrition rate (% of those recruited) | 35% | 33% | 36% | 38% | 35% | 40% | 26% | 38% | 22% | 32% | 31% | 31% | 42% | 18% | 30% | 36% | 30% | 39% | 26% | 32% |