Table 5.

Cluster randomized stepped wedge trial design

Key features	Clusters randomly cross-over from control to intervention All participant groups will eventually receive intervention Multiple levels of analysis
Advantages	Ethically more acceptable Suitable for resource-scarce environments Multiple comparisons allow for robust results with lower sample size (n) Allows for longer term longitudinal observations of intervention
Disadvantages	No downstream analysis possible as controls disappear Group may be dissimilar affecting results Temporal confounding Power analysis complex Complex results analysis
Example	Gambia Hepatitis Intervention Study15