Best evidence synthesis used in this article
| Strong | Generally consistent findings (≥75%) in multiple high-quality longitudinal studies |
| Moderate | Generally consistent findings (≥75%) in multiple low-quality longitudinal studies and/or positive findings in one high-quality longitudinal study |
| Limited | Findings in one or more low-quality longitudinal studies |
| Conflicting | Inconsistent findings among multiple longitudinal studies |
| No evidence | No longitudinal studies, either observational cohorts or RCTs, could be found |
RCT, randomised controlled trial.