| Study category | Study design | ||
| Experimental | RCT/CCT | HCT | Cross‐over RCT |
| Non‐randomised analytical (specifically designed to assess association) | Prospective/retrospective cohort | Case‐control | Cross‐sectional |
| Non‐randomised comparative (not specifically designed to assess association) | Case cross‐over/time series | Ecological study | Indirect comparison (before and after) |
| Non‐comparative | EXCLUDE | ||
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