Common similarities and differences between the design of classical and pragmatic RCTs
| Feature of trial design | Classical RCT | Pragmatic RCT |
| Randomisation | Yes | Yes |
| Control group | Yes | Yes |
| Setting/ecology of care | • Highly controlled • Specialised centres (secondary or tertiary) | • Pragmatically controlled • Usual care (> primary care) |
| Patient population | • Highly selected • Confirmed diagnosis Narrow (“pure”) population | • Pragmatically selected • Clinical diagnosis Broad (“real-life”) population |
| Inclusion/exclusion criteria | Many | Few |
| Adherence | Very good (stimulated and monitored) | Low (real-world adherence) |
| Therapy | • Blinded (single- or double-blind); or • Open-label | Usually open-label to allow for effects of different technologies e.g. device or mode of administration |
| Comparator | Placebo; and/or active treatment | Active treatment |
| Outcome | Efficacy | Real-life effectiveness (comparative effectiveness) |
| Safety | Usually short-term | Short-term and long-term |