References | Reasona | Measures discussed or reported | Motivation for applicationb |
---|---|---|---|
Randomized controlled trials | |||
D’Amelio et al. [27] | Mediation | Natural direct and natural indirect effects Emphasized direct effect | Improve understanding to show that above and beyond how the treatment works through the mediator, there is an independent effect |
Freeman et al. [28] | Mediation | Direct and indirect effectsc Proportion mediated by various factors | Improve understanding of mechanisms |
Cohort studies | |||
Banack et al. [26] | Mediation | Similar to controlled direct effect (with caveat that no manipulation of obesity could actually occur) | Refute/confirm that selection bias drives the obesity paradox in cardiovascular disease |
Jackson et al. [29] | Mediation | Natural direct and indirect effects Proportion mediated by each medical event | Improve understanding of mechanisms |
Kositsawat et al. [30] | Mediation | Not identified | Not clear |
Louwies et al. [31] | Mediation | Direct and indirect effectc | Improve understanding of mechanisms |
Lu et al. [32] | Mediation | Natural direct and natural indirect effect Percent excess risk mediated Natural indirect effect emphasized | Improve understanding of mechanisms |
Mendola et al. [33] | Mediation | Controlled direct effect | Improve understanding |
Messerlian et al. [34] | Mediation | Controlled direct effect | Improve understanding |
Raghavan et al. [35] | Mediation | Direct and indirect effects but only indirect effects reportedc Proportion of risk mediated through genetic and metabolic factors | Improve understanding of what mediators might be ripe for intervention |
Case control studies | |||
Rao et al. [36] | Mediation | Controlled direct effect | Improve understanding |
Song et al. [37] | Mediation | Effect not mediated mediated effectc Proportion mediated through various biomarkers | Improve understanding of mechanisms |
Xie et al. [38] | Mediation | Direct and indirect effectc Proportion of effect mediated through testosterone | Improve understanding |