Table 1.
Placebo iRCT |
Active iRCT |
Stepped-wedge or ring-vaccination trial |
|
---|---|---|---|
1. General | |||
a. The study intervention is needed urgently for many people. | ✓ | ✓ | ✓ |
b. No study assignment involves a procedure that is expected to actively harm any participant more than it directly benefits her. | ✓ | ✓ | ✓ |
c. No intervention for the condition studied is approved (and available to candidate participants). | ✓ | ✓ | ✓ |
2. Participant access to study intervention | |||
a. All participants receive the study intervention during the trial—except ones who die or get infected before the intervention reaches them. | – | – | ✓ |
b. All participants receive the study intervention during the trial or shortly thereafter—except ones who die or get infected before the intervention reaches them. | ✓ | ✓ | ✓ |
c. For any prespecified level of statistical power to detect a given effect size, typically the number of participants who die or get infected before the study intervention reaches them is minimal. | ✓ | ✓ | – |
3. Impact on participants’ prospects | |||
a. Participation improves medical prospects for each participant (both before and immediately after randomisation) more than any alternative available outside the trial. | ✓ | ✓ | ✓ |
b. Participation improves medical prospects for each participant (both before and immediately after randomisation) more than any alternative, including even alternatives that compromise trial efficiency or validity. | – | – | – |
c. Participation improves medical prospects for each participant (both before and immediately after randomisation), making their prospects better than those of relevant non-participants. | ✓ | ✓ | ✓ |
d. Equipoise (understood here as equal medical prospects in all arms immediately after randomisation) obtains. | – | – | – |
e. In no trial arm do the typical participants have grim medical prospects (immediately after randomisation). | ✓ | ✓ | ✓ |
For simplicity, the table assumes trials with two equally sized arms.