2
votes
1answer
162 views

Moderation in repeated-measures design?

Context: Both dependent $(Y_1,~Y_2,~Y_3)$ and independent $(X_1,~X_2,~X_3)$ variables were measured repeatedly at three time points, $\text{Time}_1$, $\text{Time}_2$, and $\text{Time}_3$. Moderator ...
5
votes
2answers
174 views

Plotting and presenting longitudinal data, options?

Hypothetical Scenario: A few continuous variables, each measured repeatedly at, say 12 time points, each with say, 150 observations. There are small fluctuations from one time point to another (i.e. ...
0
votes
0answers
136 views

Interpretation of interaction and main effect in a mixed model when one is significant and the other is not

I have repeated (x4) measurements on 90 subjects. The outcome is zero inflated. The model output gives these estimates: ...
4
votes
1answer
345 views

Multiple regression with repeatedly measured independent variables?

Design and hypothesis: we measured wellbeing at Time-1 and Time-2, we want to see whether factor A (measured at Time-1 and ...
2
votes
0answers
81 views

Nested repeated measures analysis

I have a nested repeated measures question. I have 20 individuals grouped into 5 families. For each individual I have measurements on subsequent days pre, during, and post-treatment for a total of 6 ...
1
vote
1answer
160 views

The test procedure of significant differences in count data over time

The data below are from a health testing centre over 8 years so there are different people being tested there each year. All I really want to show is that the amount of females being tested is ...
12
votes
1answer
388 views

Is there an R package for continuous time longitudinal binary responses?

The bild package appears to be an excellent package for serial binary responses. But it is for discrete time. I would like to specify a smooth function of time ...
1
vote
1answer
173 views

How to model repeated measures with time-varying covariates in SPSS?

I wanted to test the effectiveness of a particular type of "talking" therapy on depression. I envisaged selecting ONE group of people and measuring their heart rate and scores on depression scale for ...
1
vote
0answers
41 views

Looking for pointers on how/if to model a “low t and high n” longitudinal data set to evaluate outcome-predictors

Say you have a longitudinal data set with 5 measurement points, which begins at 200-300 participants and declines to about 50. There is an intervention between time-point 2 and 3. There's 3 continuous ...
2
votes
1answer
254 views

Repeated measures ANOVA

I have to apologise about my lack of experience but hopefully someone can clarify things for me. I am interested in looking at change in psychosocial functioning over time and compare it between ...
2
votes
2answers
268 views

repeated measures regression

I was hoping that I could get some feedback in terms of keywords I should searching for, or concepts I need to consider with the following: I have non-experimental data that I would like to model in ...
6
votes
3answers
513 views

Repeated measures structural equation modeling

I need to analyse a dataset of clinical rehabilitation data. I am interested in hypothesis-driven relationships between quantified "input" (amount of therapy) and changes in health status. Although ...
7
votes
2answers
797 views

Longitudinal data: time series, repeated measures, or something else?

In plain English: I have a multiple regression or ANOVA model but the response variable for each individual is a curvilinear function of time. How can I tell which of the right-hand-side variables ...
3
votes
2answers
304 views

Best model for change in scores over three time points

I have a response variable measured at three time points per individual (week 0, 18, and 36). I am interested in differences in the change of the response over the 36 weeks within some categorical ...
8
votes
1answer
263 views

Can slopes in linear regressions be used as the independent or dependent variables in other regression models?

I have 100 patients and each patient have 10 longitudinal serum creatinine measurements. The estimated glomerular filtration rates (eGFR) were calculated from a MDRD formula comprising gender, age and ...
7
votes
3answers
3k views

What is the difference between using aov() and lme() in analyzing a longitudinal dataset?

Can anyone tell me the difference between using aov() and lme() for analyzing longitudinal data and how to interpret results ...