Questions tagged [mediation]

A mediator is a variable that plays an intermediate role in a causal chain. Ie, the 1st variable in the chain causes the mediator, which in turn causes the 3rd variable. Partial mediation is when the 1st variable causes the 3rd both through the mediator & directly.

Filter by
Sorted by
Tagged with
1 vote
1 answer
16 views

How to compare mediation models with one or two mediators?

I'm looking to compare the indirect effect sizes of two models: IV1 -> IV2 -> DV and IV1 -> IV2 -> IV3 -> DV Is there a way to do this in R? I know how to run the first model using the ...
user399309's user avatar
0 votes
0 answers
14 views

Proportion mediated possible for Binary outcome, Continuous mediator?

I am running a mediation analysis on a categorical X (race/ethnicity), binary Y (disease status), and ordinal M (can be any integer 0 - 10). N-controls = 1321. Ncases = 384. I conducted this analysis ...
Kris's user avatar
  • 11
2 votes
1 answer
88 views

Causal Mediation Analysis with treatment smoothed in the outcome stage and linear in the mediator stage

I am considering a mediation analysis that looks like the following in r: ...
flâneur's user avatar
  • 133
5 votes
1 answer
118 views

SEM with 50% missing data (due to distribution of items over various survey ballots/waves)

I want to test a multilevel mediation (particularly, test a number of hypotheses about possible mediators of the effect of social class on Right-Wing Authoritarianism) using largely categorical ...
ThomasV's user avatar
  • 51
1 vote
1 answer
60 views

Mediation analysis - categorical predictor - how to set hypothetical reference?

I am running a mediation analysis on a categorical X (race/ethnicity), binary Y (disease status), and ordinal M (can be any integer 0 - 10). I had originally calculated a percent mediated (coefficient ...
Kris's user avatar
  • 11
1 vote
1 answer
18 views

Mediation: only c path and b path are significant?

I have done a mediation analysis in which nature contact is the independent variable, worrying is the mediator and depressive symptoms the dependent variable. I performed a mediation via PROCESS. The ...
MAG Weimans's user avatar
0 votes
1 answer
35 views

Mediation Analysis in R with two mediators in a repeated measure experiment (within-subject design)

I'm currently facing a challenge and would greatly appreciate your assistance. I'm attempting to conduct a mediation analysis with two mediators in a within-subject design exoeriment using R. Here's a ...
nnjava's user avatar
  • 1
1 vote
1 answer
23 views

Assessing bivariate change (pre- and post-intervention) when sample size is small and there is no control group?

I have data from a randomised control trial of approximately 60 people (30 people in the intervention group, 30 in the control group). I would like to assess whether change in one variable (M) is ...
Aepkr's user avatar
  • 189
0 votes
0 answers
26 views

ACME Significant in Mediation analysis, but not Proportion Mediated and Fitting terminated with step failure warning

I am running a series of mediation analyses in R using the mediation package and the following code: ...
flâneur's user avatar
  • 133
0 votes
1 answer
15 views

Mediation analysis with between & within subjects?

I have a RCT data set as follows: IV = Group (Intervention A, Intervention B, Control) DV = Blood biomarker, Inhibitory control, working memory I have two research aims. Comparing the effect of ...
user409631's user avatar
2 votes
1 answer
38 views

moderated mediation vs mediated moderation

I am looking for a detailed explanation of moderated mediation and mediated moderation. My basic understanding is that in moderated mediation, we have a classical mediation model with the addition of ...
Cooper Owls's user avatar
1 vote
0 answers
28 views

Significant index of moderated mediation but no significant interactions of moderators

I ran Hayes process Macro 8 in SPSS. In my results below, you'll see the index of moderated mediation is significant; however neither of the interactions in this model are significant. Model is below. ...
user409598's user avatar
0 votes
0 answers
17 views

Is a multicategorical multilevel mediation even possible?

I've tried to model a multicategorical multilevel mediation by using the logic of Hayes et al., 2014 on multicategorical mediation and an implementation of a multilevel mediation. Here's a MWE: ...
brizzen's user avatar
1 vote
1 answer
15 views

Group Comparison with serial mediation

I'm trying to compare two groups for a serial mediation model. I wrote my code like in this link to make it clearer, here is my code: ...
Cavdar_A's user avatar
0 votes
0 answers
5 views

Question about SNPs selection in Mendelian randomisation for mediation analysis

I recently read the paper entitled "Mendelian randomisation for mediation analysis: current methods and challenges for implementation". https://doi.org/10.1007/s10654-021-00757-1 I am still ...
BOO's user avatar
  • 53
3 votes
1 answer
36 views

Completely standardized indirect effect (Preacher & Kelley, 2011) in lavaan

Preacher & Kelley (2011) have proposed an effect size (i.e., completely standardized indirect effect) that quantifies the magnitude of an indirect effect. My question is whether lavaan's ...
Matthias's user avatar
0 votes
0 answers
31 views

Apply custom (ANOVA-like) contrasts to all interactions in a mixed model (with a stacked dataset)

I am conducting a multilevel mediation analysis with a multicategorical X (4 levels from a 2-by-2 design) for which I want to apply custom contrasts that code two ...
brizzen's user avatar
5 votes
3 answers
167 views

Reading tips on longitudinal mixed models and mediation

I'm a Swedish PhD student in psychology looking for advice on what to read to understand linear mixed models in a longitudinal context better. We're running a RCT with two active groups and weekly ...
0 votes
1 answer
33 views

Simple mediation analysis - significant indirect effect but no significant total or direct effect

I've done a simple mediation analysis, but not completely sure how to interpret the findings. I've found a significant (just) indirect effect, but no significant direct or total effect (see below). I'...
LN123's user avatar
  • 1
0 votes
0 answers
43 views

Can I ignore "Control" and "Treated" from the output of the mediation package if my predictor is continuous?

I am trying to run mediation analysis to see if one continuous biological variable mediates the relationship between another continuous biological variable and a time-to-event survival outcome. I am ...
womy's user avatar
  • 85
1 vote
1 answer
43 views

Moderation and Mediation model

I am trying to fit a moderation mediation model (please see the figure) So I have a clasic mediation model and a moderator for the association between the mediator and the outcome. I want to fit this ...
JuanJMV's user avatar
  • 11
2 votes
1 answer
74 views

Comparing path analysis models: mediation vs. (residual) covariance

I am using lavaan to run path analysis to predict PC from WA and LC. These are multi-group models. Described here is the first step (identifying best-fitting paths); it is followed by constraining ...
Jeanne Sinclair's user avatar
0 votes
1 answer
64 views

How can I improve my mediation analysis to account for repeated measures (2 time points)

We are currently trying to test a mediation model with repeated measures (two time points) for a 1-1-1 level analysis. My independent (TreatmentF), mediator (Ambivalence), and dependent variable (...
Marije van Gent's user avatar
1 vote
0 answers
25 views

How to perform multilevel moderated mediation analysis with {mediate}

I'm attempted to run a multilevel moderated mediation analysis in R using the mediate package. Some details on my sample: I have an experimentally manipulated ...
Ethan Milne's user avatar
0 votes
0 answers
31 views

Conducting a moderated multilevel mediation with more than two levels in R

I'm trying to conduct a moderated multilevel mediation model in R, but I'm still a pretty junior graduate student and I've only ever done mediation with lavaan. My outcome variable is cortisol, for ...
calexico's user avatar
0 votes
1 answer
24 views

Total scale is a significant mediator, but not subscales?

I am running mediation analysis where there is a significant mediating effect through the total scale for the construct I'm looking at. However, when I run a parallel mediation using the subscales in ...
stats student's user avatar
1 vote
0 answers
35 views

mediation in R - interpretating the absolute value of total effect, ACME, and ADE (binary exposure, mediator, and outcome)

I am a beginner of mediation analysis. In my research, exposure, mediator, and outcome are binary (0: no, 1: yes). The data is clustered by unit. I have fitted the mediate model (M ~ E) and outcome ...
chen liang's user avatar
2 votes
1 answer
61 views

Seeking References for Mediation and SEM Best Practices

Preamble Recently, a colleague approached me with a dataset$^1$ that they wanted to use to compare several competing mediation models using structural equation modeling (SEM). The models are simple, e....
Preston Botter's user avatar
0 votes
1 answer
41 views

Simple mediation analysis in PROCESS 4.2 in SPSS. The outcome variable is binary, the mediator is continuous and the IV is binary

In the first model, the IV (X) significantly predicts the mediator (M). In the second model, the mediator significantly predicts the outcome variable (Y) but the IV (X) does not predict the outcome ...
lisaarthur's user avatar
0 votes
0 answers
14 views

Question regarding control variables in a serial mediation model

i encountered questions regarding running a serial mediation model in mplus. my IV is ERS(excessive reasssurance seeking) DV is depression (DEP), my proposed two mediators are INU (internet use) and ...
Claire Cheng's user avatar
1 vote
0 answers
38 views

What does it mean when the total effect is non-significant in a mediation?

I ran a mediation analysis using lavaan, there was a significant indirect effect but no significant direct or total effect. What does the total effect mean and how do I go about interpreting this ...
stats student's user avatar
0 votes
0 answers
14 views

How to carry out mediated moderation with three groups

I have the results of an experiment that is set up this way: I'm testing the effects of a human vs non-human stimulus on the dependent variable, an effect which is mediated by a mediator. Simple ...
SJ Lin's user avatar
  • 1
0 votes
1 answer
48 views

SEM, path analysis without latent variables

If the mediation analysis includes only observed variables, would it be necessary to test the measurement model and conduct a CFA prior to path analyses? Are there other analyses, on top of ...
Ben's user avatar
  • 3
0 votes
1 answer
30 views

Path analysis: Mediation and linear regression reporting

Let's say I'm testing this relationship in a path analysis in SPSS AMOS to answer these 2 research questions: Does worker's moral have a significant positive relationship with organisation ...
Simon's user avatar
  • 245
0 votes
1 answer
51 views

How to perform inference in a simple mediation analysis?

I am running a very simple version of a mediation analysis with five variables, $y, x, t, z1, z2$. It's simple in that I am only including the mediated effect. I first run $y = x + t + e1$. Next, I ...
mirrror's user avatar
  • 43
1 vote
0 answers
11 views

Moderated Mediation

Does anyone know the process model # for a moderated mediation, where the independent variable (in this diagram A) moderates the effect of the mediator (B) on C? I attached a diagram below. ...
ElleEh's user avatar
  • 11
1 vote
1 answer
36 views

Mediation analysis not producing expected results, probably as consequence of multicollinearity issue

I am using the PROCESS macro to do a basic mediation analysis, with variables X,M, and Y. All are continuous. I know from theory that X and M, and M and Y respectively, should have a relationship. I ...
Maarten 's user avatar
1 vote
0 answers
8 views

Time being a mediator of sort but planned on used time varying cox ph model?

I am working on a project where literature has traditionally treated the exposure as a time-dependent exposure and used a time varying cox ph model. During the logistic, and normal cox PH analysis ...
user402261's user avatar
3 votes
1 answer
32 views

Mediation analysis - Hayes Process plugin

I have a model to test 4 hypothesis (all data was collected on a 5-point likert scale through surveys): Ability (IV) has a positive relationship with PO fit (M) PO fit (M) has a negative ...
Simon's user avatar
  • 245
0 votes
1 answer
40 views

Variance for Serial Meditation (Model 6)

I have this SPSS output and I'm wondering how I report variance for the model. Additionally, how much of the variance was explained by exercise both directly and indirectly (through both mediators) in ...
CatahoulaLola's user avatar
0 votes
0 answers
44 views

mediator or moderator in R?

Hello I am learning how to decide whether a variable is a moderator or a mediator in R. For my knowledge, if the interaction term is not statistically significant, we need to consider the mediating ...
Fox_Summer's user avatar
2 votes
1 answer
46 views

Mediation analysis with interaction effect

I am currently trying to amend a paper that I am writing in order to include the interaction effects (a4 and b4 in the spreadsheet) This results in the following sum-product $$a_1b_1 + a_2b_2 + a_3b_3 ...
Sam Levi's user avatar
1 vote
1 answer
9 views

Is mediation analysis appropriate to study the effect of outdoor temperature on surface temperature, which also affects underside temperature?

I hypothesise that the higher the outdoor temperature, the higher the surface temperature of the building envelope, which should also translate into the detection of higher surface temperature on the ...
user401174's user avatar
0 votes
0 answers
31 views

Interpeting Mediation R package with binary mediator and binary outcome

I have a question concerning he Mediation R package concerning the interpretation of the estimates. I'd like to interpret the results of the Mediation package output. Let's say I have a binary ...
Christo's user avatar
1 vote
0 answers
48 views

Interpretation of Multilevel Mediation

I am attempting to perform a multilevel mediation and found this page online with an example: https://stats.oarc.ucla.edu/r/faq/how-can-i-perform-mediation-with-multilevel-data-method-2/ It follows a ...
Paul's user avatar
  • 56
1 vote
1 answer
47 views

biased estimation of variable correlated with endogenous variable

I have the following model: $ X = \alpha_1 + aZ + \epsilon_1 \\ Y = \alpha_2 + bZ + cX + \epsilon_2 $ Suppose that $Z$ is randomly assigned but $X$ is correlated with the error term $\epsilon_2$, in ...
Eaman's user avatar
  • 31
0 votes
1 answer
18 views

Questions regarding indirect effects mediation regession

I am trying to test the significance of the total indirect effects of 3 variables and I am required to use multiple regression modelling (the mediators were unintended). While I found an equation from ...
Schmuel Levi's user avatar
0 votes
1 answer
110 views

Serial mediation with 3 mediators and 2 predictors [lavaan]

I have constructed a structural equation model in R using lavaan, with 2 exogenous predictor variables, 3 mediators, and 1 endogenous response variable: I tried to label it as conventionally as ...
Atanaqui's user avatar
1 vote
0 answers
28 views

Can you run a mediation analysis using beta regression

When running a beta regression in R I am interested in seeing if there are any potential mediators to my primary outcome. My primary outcome is bounded between 0 and 1 and I therefore am unsure I can ...
Jack's user avatar
  • 11
0 votes
0 answers
156 views

how to run mediation analysis after multiple imputation in R?

I have run a multiple imputation model and after it I used the with() and pool() functions to pool all my results using linear regression to get one estimate. I want to run mediation analysis on this ...
yusefsoliman's user avatar

1
2 3 4 5
11