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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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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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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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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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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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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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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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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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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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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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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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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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 ...
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covariate-adjusted analysis for time to event endpoint in a cross over design RCT
I have a time to event endpoint in a 2x2 crossover RCT which I would like to analyse with a regression model to adjust for covariate effects. I am supposing I cannot fit a Cox proportional Hazards ...
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Parafac for crossover design studies
.Hi, everybody
I have data that has 28 subjects involved in a crossover design study including 4 different treatments. The amount of variables is over 10000 (measured almost on the same scale)
In ...
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Sample size calculation for crossover design using dependent t-test - role of $\rho$?
I am trying to do a sample size calculation for a 2x2 crossover study. I have access to previous studies whereby I can get covariate adjusted estimates of the variability of the responses (from a ...
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Analysis of pre-post data when 2 treatments given serially to same subjects
I have following data from a cross-over trial where subjects were given 2 types of treatments separated by a washout period. For each treatment measurement was made in pre and post treatment period. I ...
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is there no need for a washout period when using Balaam Design
Balaam design is a crossover design for comparison of regimen A with regimen B in which subjects are randomly allocated to one of four sequences: AA, AB, BA or BB. Sequence AA means that the ...
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repeated measures ANOVA, crossover trial, R
I am sorry for stating such a question. Unfortunatelly, it's very-very hard to go through all statistics.
I have a crossover study design with 3 treatments, 3 periods, and a baseline (covariate).
The ...
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What is the meaning of the beta-coefficient for an interaction term in a crossover study?
I have asked a similar question here: stackoverflow I am puzzled by the interpretation for an interaction term. In my data my Y is an interval variable with the health outcome of an experiment. I have ...
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stepped wedge and additive intervention effects
Let's say we want to randomize 400 caregivers to a parenting intervention or a wait-list control group. But we also want to look at a program variation for a sub-sample of caregivers of children with ...
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How to display error bars for cross-over (paired) experiments
The following scenario has become the Most-FAQ in the trio of investigator (I), reviewer/editor (R, not related to CRAN) and me (M) as plot creator. We can assume that (R) is the typical medical big ...
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How to analyze ordinal repeated measures data
I have data from an ordinal scale, with the score ranging from 1-4. Each subject has 9 assessments on this scale (study is a 9-way crossover design), and there are no missing data. What is the ...
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What statistical analysis is most appropriate for a cross-over treatment design? How many participants?
I am asking on behalf of a colleague. I was hoping to have an answer for him, but I rather seek some guidance and be a bit more confident. He is designing a treatment study, which I am inventing here ...
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How to compare task completion times in a crossover study
Ten participants have completed a task using two different methods A and B. The first five participants completed the task first using method A then B. The remaining participants completed the same ...
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