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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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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Cross Over design with repeated measurements

I want to see if there is a difference between treatment A and treatment B. Same individual will undergo treatment in order AB or BA. For each treatment, measurements will be made at 7 different time ...
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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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“drop the loser” or futility in crossovers with more than 2 treatments

I wonder if anyone can advise me if there are methods (or even a concept) of dropping losers for futility in crossover trials For exampe if I have 4 treatments (A,B,C and D - and maybe all 24 possible ...
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323 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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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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249 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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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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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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873 views

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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359 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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228 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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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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What is this design and how can I analyze it?

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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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680 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 ...
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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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212 views

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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63 views

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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One sided p value in a crossover trial

A test treatment was compared with the control treatment in a cross-over trial with 10 patients. The test treatment was superior in 8 patients and the control was superior in other 2 patients. What is ...
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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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A randomized, double-blind crossover (AB/BA) observational study of new use of an FDA approved drug

I found a new use of a drug already in use. The results are as follows. Serail No. of Patient-- Attacks while on Placebo-- Attacks while on drug --Difference in the no. of attacks 1- 23- 2- ...
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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 ...