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| Underlying methodology | Quality rating |
| Randomised trials; or double‐upgraded observational studies. | High |
| Downgraded randomised trials; or upgraded observational studies. | Moderate |
| Double‐downgraded randomised trials; or observational studies. | Low |
| Triple‐downgraded randomised trials; or downgraded observational studies; or case series/case reports. | Very low |
