Stepped wedge study design of OPTI-AGED trial
| Initiation | Step1 | Step2 | Step3 | Step4 | Step5 | |
| Cluster 1 | Control | Control | Control | Control | Control | Intervention |
| Cluster 2 | Control | Control | Control | Control | Intervention | Intervention |
| Cluster 3 | Control | Control | Control | Intervention | Intervention | Intervention |
| Cluster 4 | Control | Control | Intervention | Intervention | Intervention | Intervention |
| Cluster 5 | Control | Intervention | Intervention | Intervention | Intervention | Intervention |
Six intervals of 4 months will be fixed over 24 months.
The randomisation will involve five steps for which 5–6 centres will be included in each cluster.