Table 3.
How Adaptive Randomization Using Minimization Works
| Prognostic factor | Control group | Treatment group | |
|---|---|---|---|
| If allocated to control group | Site | ||
| Site 1 | 1 | 0 | |
| Site 2 | 1 | 1 | |
| Sex | |||
| Male | 1 | 1 | |
| Female | 1 | 0 | |
| Age band | |||
| < 20 | 1 | 0 | |
| 20–64 | 1 | 1 | |
| ≥ 65 | 0 | 0 | |
| Total number of imbalances | [(1 − 0) + (1 − 1) + (1 − 0)] = 2 | ||
| If allocated to treatment group | Site | ||
| Site 1 | 0 | 1 | |
| Site 2 | 1 | 1 | |
| Sex | |||
| Male | 0 | 2 | |
| Female | 1 | 0 | |
| Age band | |||
| < 20 | 0 | 1 | |
| 20–64 | 1 | 1 | |
| ≥ 65 | 0 | 0 | |
| Total number of imbalances | [(1 − 0) + (2 − 0) + (1 − 0)] = 4 | ||
The third patient has factors sex male, 17 yr, and site 1. If this patient is allocated to the control group, the total imbalance is 2. If this patient is allocated to the treatment group, the total imbalance is 4. Therefore,this patient is allocated to the control group, and then site 1, sex male, and the < 20 age band in the control group receive the score.