Questions tagged [medicine]
The medicine tag has no usage guidance.
167
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Defining clinical follow-up: Fixed Period vs. Maximum Duration
We are retrospectively analyzing data of around 1100 patients operated between 2017 and 2023. We analyzed follow-up documentation until 2024. This means that patients operated at a later date will ...
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35
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Linear models to compare SNP categories between patients
I have 8 patients (GROUP: 3 healthy, 5 disease). For each patient, I determined single nucleotide polymorphisms (SNPs) and annotated the effect of the SNPs (EFFECT_CATEGORY). Each SNP (~3000 per ...
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Are diagnostic tests and clinical (risk) prediction models in medicine essentially the same thing?
In medicine, are diagnostic tests (e.g. covid test, HIV test, ...) and risk prediction models essentially the same thing? If not, in which aspects do they differ (from statistical point of view)? ...
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What data are used to find the final threshold for a medical diagnostic test?
Suppose I have some blood measurement X whose values correlate with some disease Y (so people with the disease use to have larger values of X). Moreover suppose that the disease is rare, say 1% of a ...
- 3,989
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Mixed modal MANOVA or something else?
I am once again asking for your help. I am developing a research proposal and I am a bit confused. I have a randomized controlled trial (RCT) for testing the efficacy of a therapeutic intervention, in ...
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48
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Cohen's d effect size of a medication
Studies use Cohen's d effect size to convey the effectiveness of an intervention. As a general rule in psychology, an effect size of 0.2 is considered small, 0.5 is medium, and 0.8 is large.
Suppose ...
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How to check if an intervention helps a continuous variable (angle) stay within normal limits?
I have two different surgical interventions, and they are both used to treat cervical stenosis. One of the predictors of long-term success is the spinal alignment (relative angles of the vertebra).
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Can Cox or Fine-Gray model include exposure that occurs during observation?
I'm making a Fine-Gray model about pregnancy, but I notice that some pregnancy complications may occur during the observation instead of at the beginning of it because those complications are often ...
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5
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Comparing the pattern of commensal of two drugs over time
I would naturally appreciate your advice on the following problem:
Following operations, patients can be started either Drug A or Drug B to prevent blood clots forming in patients calves. We surveyed $...
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linear mixed model or non-linear mixed model
I´m in the medical field and study biomarkers. I study a biomarker that after a worsening of symptom, first increase and then decrease. It´s almost like the kinetics of blood-glucose after you eat. I ...
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Determining inflection point/ threshold values from a Cox regression using cubic splines
I am interested in looking at the impact of time to diagnosis of cancer on death. I will be modelling time to dx as a continuous predictor using cubic splines. I am also interested in determining a ...
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65
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Analysis of Alzheimer data
I have two data sets with values from Alzheimer's and healthy patients. My task is to find a decision rule for evaluating the patients. The task in the original wording:
"Think of a decision rule ...
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Missing data for Cox regression and HR
I'm conducting a research in which patients went through a surgery, for some the surgery was successful (outcome = 1) and for some it wasn't (outcome = 0). The risk factors were calculated using a Cox ...
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36
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Best subgroup identification - Cox regression, biomarker performance
We are working on a blood value biomarker type (lets call it NEW_bm) for a specific disease. We got data of 4 years follow-up and did a multivariable Cox-regression to see, if it has predictive ...
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Statistical Genetics - How to interpret data & analysis
My question is how to interpret $G_{ij}$ in the following statistical genetic model $$h(\mu_i) = \alpha_0 + \alpha'X_i + \beta'G_i,$$
where $G_i = (G_{i1},\dots ,G_{im})$ are allele counts (zero, one, ...
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