Table 3 Sample sizes for a controlled intervention study with Composite Referral Completion Indicator (CRCI) as the outcome measure, based on England and Wales population structure a
Level of similarity within households in disease risk factors/level of similarly within households in level of compliance of uptake of interventions | Intervention percentage effect | Mean (SD) CRCI in control arm | Mean (SD) CRCI in CHW arm | Sample size number of households per arm based on comparison of mean CRCIs, allowing for inclusion of householdsbwithout valid CRCI: | |||
|---|---|---|---|---|---|---|---|
Without clustering of intervention by region | With clustering of intervention by regions of 100 households, Intra-CHW ICC = 0.01 | With clustering of intervention by regions of 100 households, Intra-CHW ICC = 0.02 | With clustering of intervention by regions of 100 households, Intra-CHW ICC = 0.05 | ||||
Typical distribution across England and Wales: none/none | 10% | 0.56 (0.36) | 0.61 (0.36) | 1,650 | 3,280 | 4,920 | 9,820 |
none/none | 20% | 0.56 (0.36) | 0.65 (0.35) | 400 | 800 | 1,190 | 2,380 |
none/none | 30% | 0.56 (0.36) | 0.69 (0.34) | 170 | 340 | 510 | 1,010 |
none/high | 10% | 0.56 (0.41) | 0.61 (0.39) | 1,970 | 3,920 | 5,870 | 11,720 |
none/high | 20% | 0.56 (0.41) | 0.65 (0.38) | 490 | 980 | 1,460 | 2,920 |
none/high | 30% | 0.56 (0.41) | 0.69 (0.36) | 210 | 420 | 630 | 1,250 |
high/none | 10% | 0.6 (0.37) | 0.64 (0.36) | 1,990 | 3,960 | 5,930 | 11,840 |
high/none | 20% | 0.6 (0.37) | 0.68 (0.35) | 490 | 980 | 1,460 | 2,920 |
high/none | 30% | 0.6 (0.37) | 0.72 (0.33) | 210 | 420 | 630 | 1,250 |
high/high | 10% | 0.6 (0.41) | 0.64 (0.39) | 2,470 | 4,920 | 7,360 | 14,700 |
high/high | 20% | 0.6 (0.41) | 0.68 (0.38) | 590 | 1,170 | 1,760 | 3,510 |
high/high | 30% | 0.6 (0.41) | 0.72 (0.36) | 250 | 500 | 750 | 1,490 |
Typical distribution of deprived areas none/none | 10% | 0.57 (0.36) | 0.61 (0.35) | 1,650 | 3,280 | 4,920 | 9,820 |
none/none | 20% | 0.57 (0.36) | 0.66 (0.34) | 400 | 800 | 1,190 | 2,380 |
none/none | 30% | 0.57 (0.36) | 0.7 (0.33) | 170 | 340 | 510 | 1,010 |
none/high | 10% | 0.57 (0.4) | 0.62 (0.39) | 1,970 | 3,920 | 5,870 | 11,720 |
none/high | 20% | 0.57 (0.4) | 0.66 (0.37) | 480 | 960 | 1,430 | 2,860 |
none/high | 30% | 0.57 (0.4) | 0.7 (0.36) | 210 | 420 | 630 | 1,250 |
high/none | 10% | 0.6 (0.36) | 0.64 (0.35) | 2,010 | 4,000 | 5,990 | 11,960 |
high/none | 20% | 0.6 (0.36) | 0.68 (0.34) | 480 | 960 | 1,430 | 2,860 |
high/none | 30% | 0.6 (0.36) | 0.72 (0.33) | 210 | 420 | 630 | 1,250 |
high/high | 10% | 0.6 (0.4) | 0.64 (0.39) | 2,400 | 4,780 | 7,150 | 14,280 |
high/high | 20% | 0.6 (0.4) | 0.68 (0.37) | 580 | 1,150 | 1,730 | 3,450 |
high/high | 30% | 0.6 (0.4) | 0.72 (0.35) | 250 | 500 | 750 | 1,490 |