Questions tagged [baseline]
A base measurement for comparison. Usually a measurement prior to treatment, of a control condition, or of the assumed population.
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Baseline Risk in XGBoost Model
I am doing a project to predict negative clinical outcomes after surgery using logistic regression and xgboost.
Upon testing a few sample patients, I see that oftentimes the xgboost model predicts a ...
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22 views
Mixed Models, LS Mean Plot, and Baselines Controlled by Random Effects
I have two questions about LS Means and LS Means plots.
I have a simple model I'm running in lme4:
lmer(score ~ group + time + group*time + (1|sub), data = df)
...
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2answers
32 views
How to check baseline covariate balance after variable ratio matching?
In my case, each active subject is matched to a variable number of control subject.
The way I can think of is to first average across the control subjects for the same active subject to make a 1: 1 ...
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1answer
349 views
how to calculate median follow-up time?
I have a hospital based dataset which conatins information on patient details. Right from their visit, drugs, diagnosis, lab tests, and death info etc.
So, now I would like to compute their follow up ...
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1answer
78 views
Analyzing impact of baseline value on change score using lmm
I'm using a big clinical data set with a the evolution of a continuous lab value over time being the dependent variable and I am interested in the impact of the baseline of this value on this ...
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Why are baseline rates often excluded from statistical power considerations?
The following (slightly edited) except comes from Georgi Georgiev - one of the most reliable sources on AB testing on the internet.
Let’s say you have 300 000 users a month visiting an e-commerce
...
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115 views
Dummy Classifier - No Skill Line on a Binary Classification Precision Recall Curve Using a Stratified Approach - How Calculated?
I am doing binary classification on a highly imbalanced data set where the positive value is about 1.6% of the dataset.
I am training and running models but I want to compare against a dummy ...
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1answer
60 views
What is the baseline model in structural equation modeling analysis, what it may look like?
I am reading (also learning) a paper using structural equation modeling (SEM) as their analysis method. Their analysis was constructed by using a correlation matrix and asymptotic variances. They ...
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52 views
Time Treatment Effects Insignificant with Baseline Interaction - Linear Mixed Effects Model
I am running a linear mixed effects model in R. I am testing the effects of psychedelics on well-being. I have a time treatment effect (everyone took psychedelics in this cohort, there is no control). ...
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46 views
First Time Point in an LS Mean Plot with Baseline Control
Hoping you can help me understanding a request that my supervisor would like me to do in an LS Mean plot. My model is the following in lme4:
DV ~ Group + Time + Group x Time + BaselineScore + ...
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1answer
17 views
For retrospective observational studies how to determine the baseline of control subjects
I understand that for the active treatment group you can consider the start of treatment as baseline. How about the control group?
It is difficulty to do matching without resolving this problem.
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2answers
70 views
Significant difference between randomized groups at baseline?
A collegaue and I are conducting a pilot study in a school, the aim of which is to assess whether an "alternative" educational tool is more or less effective than traditional teaching ...
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1answer
146 views
Baseline controls for clinical trials in mixed models through random effects?
I'm analyzing multisite clinical trial data with mixed models. I have (a) a continuous DV, (b) a grouping variable (treatment vs control), (c) baseline scores for the DV, (d) a time variable (baseline,...
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1answer
111 views
How to handle large baseline difference in a randomized trial
I have results of a randomized trial where 200 participants were randomly allocated to 2 intervention groups and outcome evaluated 1 month later.
I believe baseline differences between 2 groups are ...
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0answers
41 views
Which variable to take as reference category? [duplicate]
I'm doing a research about the relationship between investment risk tolerance and demographic factors such as age, generation, survey year, and control variables (including education levels,...) and I ...
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0answers
24 views
Why we cannot take baseline as predictor for change in this case
It is generally recommended that baseline should not be kept as predictor if change is outcome variable. Explanations for this have taken both baseline and final values as random (e.g. see here). ...
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35 views
Keeping baseline as predictor with change score as outcome in this peculiar scenario
It is generally recommended that baseline should not be kept as predictor if change score ...
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2answers
626 views
Is there a mathematical proof for change being correlated with baseline value
It is shown in answer here and at other places that difference of 2 random variables will be correlated with baseline. Hence baseline should not be a predictor for change in regression equations. It ...
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1answer
25 views
Using baseline categorical response as a predictor
I have a longitudinal data where the categorical response is collected at two-time points. I was wondering if it's possible to adjust my categorical response at baseline as a predictor and run a ...
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1answer
366 views
What are the advantages and disadvantages of including a baseline measurement variable in longitudinal data analysis?
What are the advantages and disadvantages of considering a baseline measurement variable in longitudinal data analysis? (A baseline variable could be the number of seizures each patient had per ...
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1answer
721 views
Base Error Rate
I am working for my final exam and I saw this sample question:
Given this dataset, Assume we have the following gender detection problem, given the observed hair length and height (both discrete ...
