All Questions
Tagged with lme4-nlme repeated-measures
377 questions
2
votes
1
answer
735
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How to obtain contrasts for constrained longitudinal data analysis?
I would like to apply a constrained longitudinal data analysis (cLDA) with a linear response variable of the form, y ~ Time + Treatment:Time + (1 | ID). I am using &...
CommunityBot
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-3
votes
1
answer
143
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lmer model output interpretation [closed]
I'm trying to interpret the lmer model output.
In particular, I am trying to explain 'HU mean' with pathology (which has 3 categories Healthy - HC- VSD), gender (M-...
- 334k
1
vote
1
answer
125
views
linear mixed model with repeated measures
I am trying to wrap my head around linear mixed models for repeated measures with random effects. I'm choosing to conduct this type of model due to missing values in my dataset.
I am interested in ...
- 21.5k
0
votes
1
answer
155
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Help with lmer formula for a repeated measures ANOVA
This is my first repeated measures analysis.
Subjects in two groups exercise until "peak" level. Blood is taken at baseline (prior to exercise), peak, 2hrs post, 24 hrs post, and 72hrs post. ...
- 102k
1
vote
0
answers
59
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Mixed Effects Model - Repeated Measures with considerable amount of missing data
I am testing differences in gene expression across four time-points and between treatment and control. In total, 50 individuals were recruited for the Treatment Group and 58 recruited for the Control ...
- 325
2
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2
answers
340
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What should be normally distributed for a two-way repeated measures ANOVA? R
When running a two-way repeated measures ANOVA, should:
A) the independent varibles be normally distributed?
B) should the scores between the variables be normally distributed?
Overall: should the ...
- 1,057
1
vote
1
answer
118
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How to specify a repeated measure in a Mixed Effect ANOVA?
I am trying to run a Repeated Measures Mixed Effect ANOVA in R. However, the syntax of the code is really tricky and it seems like there is not a lot of clarity on how to run it as I do my research.
...
- 102k
2
votes
2
answers
275
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Specify an lmer model for fully crossed data with replications
I have experiment data with multiple independent variables:
shape - 2 factors
color - 2 factors
...
- 6,650
2
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0
answers
26
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Using multilevel modeling to test differences in the ability of trait and state measures to predict outcomes
I'm currently trying to test whether trait is better at predicting overall/mean job performance than state anxiety and whether state anxiety is better at predicting daily job performance than trait ...
- 71
2
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0
answers
62
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How to distinguish between measurement error and within-person variability in multilevel modeling/HLM
I'm currently running a model to determine if people vary in their daily levels of variable Y, and if daily levels of variable X predict daily levels of variable Y. I collected measurements of both X ...
- 71
0
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0
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67
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LMER returns errors, but Repeated Measures ANOVA on the same data doesn't, why?
everyone!
So, I've been trying to fit a LMER for my data, which I fully described in this post .
This post, therefore, is a follow-up from the previous one. There's something intriguing me, I don't ...
- 843
1
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0
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18
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How to assess whether study strategy affects slope of repeated measurements?
I wish to assess the effect of teaching strategy on improvement in grades (slope). For this,
I plan to conduct a study where students will be assigned different teaching strategies for their tests. ...
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2
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1
answer
37
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1
vote
1
answer
31
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Need help with analyzing data from within subjects design study
I am planning to conduct a within-subjects design study, and I am wondering if data analysis can be done using multi-level analysis.
IV and DV will be continuous variables. Moderator will be binary, ...
- 102k
1
vote
1
answer
753
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Random effects in linear mixed model (LME) with repeated replicates
My question in short
How to account for repeats of replicates of a full factorial design in lmer() of the lme4 package in R?
...
- 47.4k
1
vote
1
answer
154
views
Correct specification of linear mixed model with repeated measures in R
I have a dataset with repeated measures data but I'm unsure of the specification of my model and subsequent contrasts:
In the dataset, participants responded to a measure (...
- 21.3k
2
votes
0
answers
659
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lme4: glmer() warning messages with count data mixed-effects model and how to proceed with model fit
I have fitted a GLMM with the function glmer of lme4 package.
My data consists of a repeated measures count variable, which I am trying to explain with a continuous variable (week) and some ...
- 21
0
votes
0
answers
59
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Can a mixed model random slope include a between-subjects factor in a repeated measures design?
I'm after some statistics help with generalised linear mixed models. I have built a model using glmer from the lmerTest package in R to fit my data with a gamma distribution. The formula is as follows:...
4
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2
answers
313
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Obtaining correlation between random-effects separately for 2 groups
I'm following up on this great answer. Suppose I have a cross-level interaction in my mixed-effects model below (ses*sector). My cluster-level predictor ...
- 65.9k
3
votes
1
answer
2k
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Repeated Measures with LMER: Include time as random effect?
I have a dataset of measurements of 29 patients across three time-points. The scenario can be easily simulated using:
...
0
votes
1
answer
57
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Linear mixed model with outcome measured just once, using nlme in R
I've got repeated measurements data on a continuous, time-varying exposure and a continuous outcome. The exposure was measured 1-...
- 102k
1
vote
0
answers
319
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Which mixed model in lme4 best mimics the unstructured covariance in GLS?
I have longitudinal study to analyse. M patients examined at N time points.
I want to run a marginal model via GLS estimation with unstructured residual covariance. But I want also to apply the ...
- 81
0
votes
2
answers
310
views
Anova and mixed effect models (lm4 / nlme) return complete different effects
As a continuation of a previous topic, I would like to address a similar experience.
Subjects completed an experiment in which their electrodermal activity was recorded. For each subject there are 72 ...
- 82.8k
1
vote
0
answers
164
views
Random-effects-model: different random effects for lme and lmer?
I’m very new to hierarchical/multilevel analysis, so please excuse me, if my question is basic.
I’m wondering why I get different results if I analyze my data with ...
- 82.8k
1
vote
0
answers
200
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MIxed model on repeated measurements data with only 2 observations per patient?
I've been trying to find out if it would be possible to use linear mixed models on repeated measurements data when there are only two measurements within each participant.
This paper (doi: 10.1002/sim....
- 149
0
votes
1
answer
936
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Fitting a linear mixed model on repeated measurements data, do I in- or exclude patients with only 1 observation?
I have a dataset of about 300 patients of which 100 have repeated observations of the outcome (2-6 observations per patient) and 200 have only 1 observation of the outcome.
To determine what the risk ...
- 11.2k
2
votes
0
answers
47
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Can trial-level reaction-times be used to predict subject-level scores of another task?
I would like to predict whether single Reaction-Times (RTs) in a computer task can predict subject performance on a comprehension task. For each subject, I have many RTs but only 1 comprehension score....
- 1,157
1
vote
0
answers
67
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Modeling repeated measures in a lme model (R)
Given one between-subjects (group: 2 groups), one within-subjects (time: 2 timepoints), and one continuous covariate, how would the syntax look for repeated measures data using lme in R?
At the moment,...
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1
vote
0
answers
176
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Linear Mixed Model: Multiple data points per participant at multiple time points
I am looking to compare change between pre and post time points separated by fatigue.
The data has multiple participants and each participant has 6 data points pre fatigue and 6 data points post ...
- 11
1
vote
1
answer
53
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Unbalanced repeated measures?
I am interested in the relationship between body mass and thyroid hormones in male and female birds. I have a sample size of 77 males and 28 females. Of these individual, 6 males and 1 females were ...
- 3,000
0
votes
1
answer
211
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Predicted values from a linear mixed model don't form a straight line even though no (higher order) transformations/polynomials have been specified
To assess if age is related to my continuous_outcome in my repeated measurements data, I've specified a linear mixed model with ...
- 149
0
votes
0
answers
34
views
Correct model formula to account for crossed and nested simultaneously?
I set some models to test some specific contrasts. But I'm not sure which will correctly address the repeated measurements over my individuals.
The dataset has:
id = subject id, factor with 83 levels
...
- 82.8k
1
vote
0
answers
37
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Experiment with two within-subjects and one between-subject with linear mixed models?
I need to analyze one dataset that contain two variables measured in the same subject and one across subjects.
The variables are:
id = subject id, factor with 83 levels
tissue = factor with 2 levels (...
- 175
2
votes
1
answer
165
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Ho to explore the interaction between dependent variable and covariate?
I'm conducting LMM by adding three independent variables (A, B, C) and a covariate (E) as the fixed effect, and the random intercept for each subject as the random effect in the model, as shown here ...
- 71
1
vote
1
answer
982
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Implementation of 4-level repeated measures multilevel linear mixed effects model
Prior Searches
Prior to reading below, I have searched this forum for other posts of this nature. I have a found a few, but I have not found them to be helpful to my specific challenge. Particularly, ...
- 200
3
votes
1
answer
52
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Specifying a mixed model with cross correlations and hierarchies in Lme4 syntax
My aim is to predict the quality $y$ of a food product based on measurements $x_a$ and $x_b$ on the main ingredient.
I have several batches of a food product that are evaluated for quality by ...
- 65.9k
0
votes
0
answers
156
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GLM Repeated Measures, with only two time-points (pre-post)?
I have a dataset that comprises of the same variable, measured at two different time-points (Pre-treatment and Post-Treatment). I want to check if there is an effect of Age in the results of the ...
- 13.5k
1
vote
1
answer
903
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Lmer set up for repeated measurements?
I have 139 subjects (ID), with measurements taken at two time points (Time1, Time2), at 148 brain regions, a dependent measure called volume, and a covariate called thickness.
Each subject has 148 ...
1
vote
0
answers
158
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Test for difference at each time point in panel data of long time series?
The easiest way to describe my question is perhaps with plots:
In this hypothetical data, each group has 9 subjects, and each subject's response is measured from time = 1… to 5. Is there a way to ...
- 63
15
votes
1
answer
4k
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Why is this linear mixed model singular?
I'm trying to understand why I get a singular fit when a linear mixed-effect model is fitted to the data below.
I used R lme4::lmer and the model is very simple ...
- 65.9k
2
votes
1
answer
206
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Is my mixed-effects model syntax correct ? (R,lme)
This is my first question after sign in:
when I read a paper, the author said:
"To explore the influences of X(2 group:X-,X+) on the longitudinal change in the above "OUTCOMES", we ...
- 65.9k
2
votes
1
answer
2k
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Mixed effects model adding covariate vs adding random effect
I am currently looking into mixed effect models and I am trying to understand the difference between adding a random effect and adding a covariate to a linear model.
Consider this example:
...
- 98.5k
1
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1
answer
40
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Modeling nested data using linear mixed modeling (specifically lme4)
I'll appreciate your help with conceptually understanding the models below.
I have data for 150 subjects who completed a cognitive task.
Each subject responded to four types of stimuli (A, B, C, D), ...
- 65.9k
1
vote
1
answer
253
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Crossed random effects: how do we model multiple reciprocal transplants in lme4?
I saw the previous post on "Crossed vs nested random effects: how do they differ and how are they specified correctly in lme4?" with a very nice descriptive response from @RobertLong (...
- 65.9k
2
votes
1
answer
145
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Full dataset with few repeated measures
I am dealing with a dataset with the majority of entries with one value per individual but, with three cases with 2 repeated measures each. My first approach would be to pursue linear mixed models, to ...
- 65.9k
3
votes
1
answer
1k
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Do I have to drop a random slope if I drop the fixed effect in mixed-models for model comparison?
I'm performing a model comparison using the likelihood ratio test in R with two mixed models fitted with lme4.
My model is:
...
- 65.9k
2
votes
1
answer
3k
views
Lmer Random Effects Interpretation
Sorry, I am new to linear mixed models. I run a linear mixed model and get the following Output:
...
- 65.9k
1
vote
1
answer
334
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Can you include between-subject control variables in random effect structure of mixed models if they are not fixed effects?
I tried finding similar cases and questions but failed and got even more confused because the answers seem to depend on when the questions were asked due to changes in the lme4 package. So I'm sorry ...
- 65.9k
9
votes
1
answer
773
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Confused: Why is lme4 changing techniques from Wald F tests to Wald Chisquare?
I've constructed some LMEMs that use dichotomous variables and their interactions as regressors, and I've become confused by the output. When I only assess a single interaction, using the code below (...
- 65.9k
1
vote
1
answer
486
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Residuals in LME models
Good morning everyone!
I have implemented the following lme model in r:
...
- 65.9k