Table 4.
Example of covariate-constrained randomization (adapted from Moulton 2004)[64]
| Baseline performance | |||||
|---|---|---|---|---|---|
| Allocation |
Intervention |
Control |
Difference |
||
| A |
25 |
50 |
60 |
75 |
30 |
| B |
25 |
60 |
50 |
75 |
20 |
| C |
25 |
75 |
50 |
60 |
5 |
| D |
50 |
60 |
25 |
75 |
5 |
| E |
50 |
75 |
25 |
60 |
20 |
| F |
60 |
75 |
25 |
50 |
30 |
| |
Covariate rate |
||||
| Allocation |
Intervention |
Control |
Difference |
||
| A |
80 |
60 |
75 |
70 |
2.5 |
| B |
80 |
75 |
60 |
70 |
12.5 |
| C |
80 |
70 |
60 |
75 |
7.5 |
| D |
60 |
75 |
80 |
70 |
7.5 |
| E |
60 |
70 |
80 |
75 |
12.5 |
| F | 75 | 70 | 80 | 60 | 2.5 |
A to F each represent different possible allocations for four clusters showing absolute difference between arms for mean rate of baseline performance and the mean rate of one additional covariate.