I have a hypothetical study where participants are taking drug X per standard of care. I have 3 different timepoints (baseline, therapy, post-therapy follow-ups) at which participants have biomarker sampling and echocardiograms performed.
Exploratory objective: efficacy; Exploratory...
I am conducting a sports study. I have these data and I would like to answer this question: What are the factors that best differentiate the two groups?
I have 2 groups of 17 professional athletes, 17 NBA and 17 MLB players with a total of 64 factors (kinetics and kinematics)...
I have survival times and fixed baseline values of biomarkers and risk factors ( I actually have them measured longitudinally but want to deal with the baseline values first).
I'd like to (ideally using SAS/PHREG) estimate my Cox PH model with the baseline variables in a (2/3 of data) training...
I have a problem related to statistics, and I hope that you can help me out. First, an attempt at a short version of my problem:
I have 2 data sets that consist of 3 sub-sets each that I want to compare with a methodology that takes the order of the data points into account.
I have the following problem and I would need some piece of advice to solve it:
I have a group of 28 patients (17 survived, 11 died) and I am trying to find out if some of quantities are capable of discriminating survivors from non-survivors with a ROC analysis.
For all the considered...
I calculated AUC using SPSS and the output was: 0.623, std.Error=0.056. p=0.055. lower Bound was 0.513 and upper was 0.743
How could it be that the p value is not significant and the lower Bound of C.I was more than 0.5?
Am I missing something?
I am analyzing a group of patients for which I have the values of a certain test variable X and their survival (1 or 0). I want to perform a ROC analysis and get the AUC value, and the optimal criterion by which I can divide the patients into surviving/non-surviving. The optimal criterion...
I kindly requested help about a study of mine concerning ROC curve analysis in medical diagnosis.
I use R software programme to find optimal cutoff point for a continuous variable.
Firstly, I generate a random continuous variable for a diseased and non-diseased subjects from normal...
I was trying to verify how well the lag-returns are calculated from ROC function in TTR package.
Following is the code that I am using:
startDate = "2001-01-01"
endDate = "2013-12-01"
Hello! With the premise that I am a simple biotechnologist and I've never studied biostatistics at all, I have been assigned the task of analyzing some data I've obtained from two serial lab tests.
With the first test I have no population issues, since the two groups I'm comparing are...
I am conducting a study looking at attitudes of a group to the use of music as a form of therapy for people with dementia. I want to see if they are positive, neutral or negative (at least negative or positive) in my sample (N=92). My hypothesis based on previous studies...
I am conducting a couple of ROC's to compare our sample with the results from other analyses and am a little stuck
Basically other papers have looked at specific cut offs (e.g 50) however whenever I run the analysis in SPSS my cut offs are all varied, for example 50.5, or 48.5, which...
Would be grateful for any help/pointers.
I've spent the weekend trying to work out how to do area under the curve (ROC) analyses in spss 18. I've done it a couple of years ago but just can't recall how to input the data and where to find the requisite commands! I have the...