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