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.
40
questions
1
vote
0answers
38 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, ...
0
votes
0answers
23 views
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 ...
0
votes
1answer
37 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 ...
0
votes
1answer
24 views
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 ...
1
vote
0answers
24 views
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-...
0
votes
0answers
31 views
“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 ...
1
vote
1answer
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 ...
0
votes
2answers
612 views
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 ...
0
votes
0answers
35 views
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 ...
4
votes
0answers
349 views
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 ...
1
vote
2answers
55 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 ...
1
vote
2answers
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 ...
1
vote
0answers
177 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 ...
0
votes
0answers
87 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.
...
2
votes
1answer
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 ...
2
votes
1answer
256 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 ...
1
vote
0answers
213 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 ...
2
votes
0answers
348 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 ...
2
votes
0answers
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.
...
0
votes
1answer
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 ...
1
vote
0answers
140 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 ...
1
vote
0answers
30 views
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 ...
1
vote
0answers
98 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, ...
2
votes
0answers
77 views
2
votes
1answer
226 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 ...
2
votes
0answers
490 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 ...
2
votes
0answers
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 ...
1
vote
0answers
83 views
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 ...
0
votes
0answers
53 views
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 ...
1
vote
0answers
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 ...
1
vote
0answers
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 ...
1
vote
0answers
169 views
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 ...
0
votes
2answers
6k views
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 ...
3
votes
1answer
2k views
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 ...
0
votes
0answers
88 views
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 ...
19
votes
5answers
7k views
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 ...
0
votes
0answers
716 views
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- ...
1
vote
1answer
1k views
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 ...
2
votes
1answer
1k views
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 ...
1
vote
0answers
161 views
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 ...
