Please identify a quantitative research article evaluating mediation in your field and provide the citation.
Fotso, Jean-Christophe, Alex C. Ezeh, and Hildah Essendi. "Maternal health in resource-poor urban settings: how does women's autonomy influence the utilization of obstetric care services?" Reproductive Health 6.1 (2009): DOI: 10.1186/1742-4755-6-9
What is the primary discipline of the authors? Reproductive health researchers in academia and at the Population Counsel
What is the exposure of interest? women's autonomy
What is the outcome of interest? place of delivery in resource-poor urban settings
What is the hypothesized mediator of interest and how is it measured? Women's education coded as none; primary; and secondary or higher
Describe the modeling approach and briefly report the estimated total, direct, and indirect effects (if these are reported).
First, multivariate models are used to identify factors associated with place of delivery and quantify their net effects. The effect of women's overall autonomy was insignificant and counter-intuitive, with low autonomy women the least likely to deliver in appropriate health facilities. The effect of household wealth on the choice of place of delivery appeared to be strong and in the expected direction (coefficient = 0.438 for less poor households).
Second, interaction models are examined to test the extent to which the effects of women's autonomy on choice of place of delivery vary by household wealth. The interaction between wealth and autonomy was largest in the poorest with middle and high autonomy. Being in the middle and higher wealth groups and having high autonomy was slightly predictive of facility birth.
Third, we examine the potential mediating effect of women's autonomy on the link between education and place of delivery by adjusting the effect of education for autonomy and assessing the change in the coefficients. The change in coefficient when adjusting for education was significant in both crude and full models.
If the direct effect is reported, would you describe this as a natural direct effect, a controlled direct effect, or something else? I think the effect reported is the controlled direct effect because the mediator is fixed.
Do you think there is potential measurement error in the mediator and how would that affect the results? There could be measurement error because the quality of the education may not be comparable between communities and therefore the levels used in the analysis may not be meaningful.
Do you think there are unmeasured confounders of the mediator-outcome association and how would that affect the results of the mediation analysis? I think use of contraception may be an interesting addition to this question because of the role education has in that decision. It may mirror the understanding gained by including number of antenatal visits – capturing something about access to the system and history of engaging with it.
Do you have any critiques of the paper? The whole sample were women living in slums. Being able to compare to a different population would have increased the understanding of autonomy and health outcomes. I wonder about the relationship between autonomy over health decisions in the setting of little autonomy over economic position. Though autonomy was looked from two different perspectives which may take care of this concern. And I do appreciate the contribution of this study to the idea that these are the women knowledge from this research can impact so focusing on them from this stage is important.