Questions tagged [crossover-study]

A crossover study is an experiment in which subjects are given a series of treatments in succession. Ideally, all orderings of treatments are used with equal numbers of subjects. Crossover studies are common in clinical trials. Carryover effects are a special concern with this design.

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to estimate treatment effect in cross over design with carry over effect

I have a cross over design (AB/BA design) with several longitudinal response variables (ordinal, nominal, continue) Carry over effect was significant. How can I estimate the effect of treatment? I ...
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How to interpret crossover-interaction between continuous and categorical variable?

I am stuck with the interpretation of my model results. In the beginning I have tested my independent variables for correlation with Theil's U and left out correlated ones to avoid multicollinearity. ...
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How to set up a voluntary interventional study to compare group-level effects?

I'm setting up a wearables study where there are a large number of standard sized groups (warehouse crews of about 300 people organized in about 7 subgroups with different skills (forklift operators, ...
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Are cross over clinical trials only suitable for drug treatments?

I wonder please if cross over trials are only applicable to drug treatments ? or maybe also to vaccines ? I can't imagine they are appropriate for surgical interventions or for devices, laser or ...
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How to calculate Residuals’s Sum Sq of 3*3 Crossover design analysis

The following program is 3*3 Crossover design analysis in R. I'd like to know how to calculate Residuals's Sum Sq "8.5089". But trying it, it was “7.29”. The image is the table in Excel, and ...
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Crossover Design with between and within group factors

I have become a little stuck with the most appropriate way to analyse my data and thought that I might seek some assistance. Thank you in advance - I am very grateful. My experiment is comparing the ...
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R: Post-hoc test on lmer. emmeans and multcomp packages

I'm working on a dataset of 2x2 crossover study. I have 10 subjects, each of them underwent both A and B treatment but in a different sequence. (This is a balanced study.) I want to see how A and B ...
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Crossover data analysis

I am currently analyzing data from a cross-over study that I represent below. It is a sample of 20 individuals. Ten individuals received treatment "A" and ten others received treatment "B" from time ...
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258 views

Statistical Analysis of fixed sequence crossover design-placebo followed by medicine

I am planning a fixed-sequence 2-treatment (placebo followed by drug) crossover study. There is a Placebo run-in period of 15 days. Placebo is the control and has no effect on BP. The aim is to ...
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Including all treatments in crossover design mixed model in SAS

I have a dataset effects of 3 treatments against ctrl on cell-lines collected from 4 donors. ...
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Cross over study participant rate

I have to look at if the participation rate in a cross over study depends on the order of treatment. Asked differently, is there a higher chance for a participant to drop out of the study after the ...
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What data analysis would be best to use for my Masters Dissertation?

I will be conducting an intervention where I will be comparing the effects of Kinesiology Tape and Placebo tape on CECS in motorcycle racers. A reading will be taken pre tape application of both ...
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How to interpret cross-over moderation?

I have these simple slope analysis graphs, are both cross-over moderation? and how to interpret each one? Thanks.
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Pooling Different Crossover Data within A Study

I am trying to analyze a double-blind study that has 3 separate crossovers: Dose X mg Dose Y mg Dose Z mg In each cohort, subjects are randomized to either 'Treatment-Placebo' or 'Placebo-Treatment'....
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86 views

Cross over design 2x2 with one baseline

I have an experiment that consist in two stages and 24 subjects between three groups. On the first stage, subjects were managed for them to answer in a certain way given the group (growth curve ...
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177 views

Equivalence of proc mixed SAS and R lme/lmer

I am looking at a 2x2 crossover study with period-specific baseline measurements and the according post-treatment outcome values Intervention (A or B) Sequence (AB or BA) Period (visit day1 and visit ...
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156 views

How to measure carryover effect in a crossover design 3x3?

I'm trying to analyse a potential carryover effect from a study with a crossover design 3x3, three treatments and three periods. My data has a latin square design with the treatment sequences CBA, ...
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23 views

Is this a crossover design?

I am working with collaborators who are conducting an education research study to see if there is a difference in learning outcomes between two learning experiences, one with a technology tool (let’s ...
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57 views

Analysis crossover clinical trial

I have data from a six-sequence 3-drug 3-phase crossover trial that had a 7-day baseline period pre-study (used to generate mean baseline value). My outcome is a non-parametric continuous variable ...
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Marginal effects in an AB/BA cross-over study

I am currently working on an AB/BA cross-over study. There I have a treatment $T$, a time-varying covariate $X$ and a dummy variables $Z$. I wish to study the interaction between $X$ and $T, Z$. I ...
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Coding of cross-over study's effects in a meta-analysis

One of the studies to be included in my meta-analysis has a cross-over design: between T1 and T2, a first group does the treatment condition while a second group does the control condition; and vice-...
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Pre-post treatment comparison crossover study 2 treatments 2 baselines

I would like to analyse data with a crossover design. Each subject was assigned to a sequence (AB or BA), i.e. 2 periods. Each period consisted of one measurement before treatment (baseline or pre-...
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Is this a valid experimental design?

An experiment to test 2 new treatments was performed in the following setup: Animals were divided into 2 groups: young (A) and old (B). Animals were present for 3 periods. Each group consisted of 81 ...
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494 views

Mathematical notation / formula of a mixed effect model

I am unsure how to define the mathematical notation of a mixed model of R. I built the model in this way: ...
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930 views

What is the difference between cross-over and repeated-measures designs?

I know that a cross-over experiment (of any number of treatments/levels) necessarily has a repeated-measures design, but that not all repeated-measures designs are cross-overs. However, I wasn't able ...
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How should I specify random effects in a crossover study with lots of repeated measures (continuous time component)?

I don't see any previous questions (with answers) about this exact thing. n=20 patients. Each took placebo then did a task for up to 60 minutes. Response (continuous variable) was measured every 2 ...
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How to analyze combined data from studies with overlap in subjects?

I have data from multiple placebo-controlled cross-over trials (each with $n \simeq 20$) with unique phenotypes measured during the placebo phase. I'd like to combine the data from these measurements ...
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How to handle crossed and nested terms in a crossover design

Here comes my case: I conducted an experiment with the following design: 30 participants, each with a unique id, were screened and classified according to a trait. Then, all participants were tested ...
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66 views

How to analyse this semi-cross over study design?

I have this semi-cross over study design. It can be depicted as two different groups - control and treatment. Patients are initially randomized into either control or treatment group. The control ...
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338 views

Regression for cross-over trial with small sample size

I am in a bit of a pickle with some data that I have obtained in a collaboration. This is a crossover trial in which 8 elite cyclists were assigned to two experimental conditions at different ...
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210 views

Analysis of a cluster crossover design

I am analyzing data from a cluster randomized cross over trial. There are 9 clusters and 3 periods in the data. The clusters are dental clinics and in each period different patients are sampled. I ...
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196 views

Correct use of T-Test?

I'm new to Cross Validated and have read some posts but I'd like to ask if I have set up this study and chosen the correct significance test. A quick rundown: Four week study Same 11 Students ...
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analytical methods for crossover study that has an addition control group

I have a crossover study where patients perform a cognitive task (with two conditions) when their brain stimulation is switched on and then off. Using a mixed effects regression, I would ensure that ...
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97 views

How does one carry out the Wilcoxon-Gehan test for paired survival data?

In a 2-way crossover scenario, where subjects are randomized in a 1:1 ratio to either a AB or BA sequence, a time-to-response variable was measured after the dosing of treatment A or treatment B. ...
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How to analyze this unusal longitudinal design?

I have data coming from an unusual design. 10 subjects were drawn to receive an experimental eye drop for reducing intraoccular pressure. One eye was chosen by random and the drops were applied. The ...
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Study the effect of 2 drugs on a symptom caused by 2 diseases

A symptom (for e.g. Headache) can be caused by 2 different diseases (X and Y). Drug “A” acts on both diseases (X and Y). Drug B acts on only second (Y) disease. Disease “X” patients will be treated ...
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How to study the effect of 2 drugs (used singly and in combination) compared to a placebo on a disease

I want to study the effect of 2 drugs (used singly and in combination) compared to a placebo on a disease. What is the best statistical method? Kindly provide full details.
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Mixed model for multiple measurements in a crossover study (SAS)

I am currently trying to analyse data from a crossover study. In brief, the study is of a crossover design, where each participant takes part in 2 separate sessions, where they play a game. This game ...
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338 views

McNemar test comparing two proportions in a crossover trial

In a crossover trial involving 50 patients, two dialysis treatment schedules were compared.Ten patients complained of vomiting on both schedules, 30 on neither, nine on treatment A only and one on ...
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278 views

Most appropriate statistical analysis for a 3 treatment, 3 period crossover design

I have a study looking at a particular blood measure after performing 3 activities (sitting (control), walking (intervention 1) and cycling (intervention 2). There will be a minimum wash out period ...
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435 views

ANCOVA for 2X2 crossover with baseline measurements - validity of assumptions

I'm trying to learn how to do ANCOVA for a 2x2 crossover study with baseline measurements. I have followed the analysis performed at Mehrotra 2014 "A recommended analysis for 2 x 2 crossover trials ...
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479 views

four period crossover design in lmer or lme4

Our experimental setting is a four-period crossover design: the table below indicates typical types of experimental data. ...
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271 views

crossover design and covariates

I wanted to use a crossover design to compare two treatments (a supplement versus a placebo) on human participants. The advantage of this design is that I don't have to worry about the effects of the ...
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153 views

Crossover study, multiple measure

I'm trying to analyze data from a crossover study, where two treatments ($A$ and $B$) are applied to $n$ patients (each patient receive both treatments). For each treatment I have an outcome with ...
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How to test if randomization influenced the results?

I did an experiment where one group of participants answered questions using an existing tool and the other group my tool, which has some additional features. Everyone received 2 tasks, one complex ...
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105 views

How to analyze fractional crossover design (factional survey experiment) with 3 factors in R?

I have the following experimental design: my treatment is composed out of three factors (factor1, factor2, ...
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78 views

What is this design and how can I analyze it?

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260 views

How to analyze crossover trial with a scale as outcome variable?

I'm working on a pilot study for a new drug. We will use a crossover design in which half of the patients will be given the drug for the first 6 weeks, then, after a washout period of one week, they ...
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615 views

a crossover repeated measure feed trial using R

I attempt to analyse a crossover feed trial using R but I`m not good at statistical analysis. My data contains 10 subjects, equally divided into 2 groups named A and B. Each group were fed with diet A ...
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913 views

Relationship between ROC (receiver operating characteristic) curve and cross-over error rate?

I do not understand this relationship. According to wikipedia, the CER can easily be obtained from the ROC curve. Equal error rate or crossover error rate (EER or CER): the rate at which both ...