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### Adjustment in DLNM - case control setting

I have data in a case-control format with a 5-year lag of exposure. I want to adjust, in addition to the strata, for the number of monitoring stations used to calculate the exposure. The problem is ...
12 views

### When is it appropriate to adjust an independent variable by regression before including it in a regression on the dependent variable of interest?

I want to run a linear mixed regression in which, basically, I see whether the expression of a particular gene is associated with a trait exhibited by the animal. I'll use growth rate as an example. ...
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### When to use an adjustment method for Kruskal-Wallis + Dunn's and which method?

I need to do multiple pairwise comparisons among 5 groups (Treatment 1, Treatment 2, Treatment 3, Positive Control, Negative Control) for different tests and times. Each group has $10$ individuals, ...
1 vote
43 views

### How to handle factors related to the exposure but not the outcome

For example, the postprandial time significantly influences blood glucose levels, with higher levels observed when the postprandial time is short. Elevated blood glucose is a risk factor for stroke, ...
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1 vote
118 views

### Why is CIHI recommending that we multiply the multiplicative error estimate by the per-capita rate?

I feel like this question is mostly about how to translate vague documentation into math than a statistics question per se, but please bear with me. I am reading the Canadian Institute for Health ...
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### Adjusting alpha for several models in which I am just using most variables to adjust

If I have a study in which I run four regression models, each containing 5 independent variables, this would result in 5*4 = 20 p-values. However, let's say the first variable is what I predict has an ...
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### P-value adjustment for different classes each tested individually

Testing the effect of a certain gene on survival of two different but somehow related (brain cancer GBM and LGG) patients, with each cancer (GBM or LGG) having several subtypes, how should I adjust ...
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### Why adjusting for randomization stratification factors in the model improves the precision of estimators for treatment effect?

I assume you will already get balanced treatment assignment within the randomization strata. Why would we still gain improvement in precision by adjusting for these factors in the model? Does not ...
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1 vote
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### Should the choice of propensity score matching versus weighting depend on the degree of overlapping of PS distributions?

I heard some opinions that matching is no good since it excludes some subjects. However, if we use PS adjustment or PS inverse probability weighting, is there a requirement on the degree of ...
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Let's assume that: we are interested in the effect of X1 on Y that our data suits well for hierarchical modelling different cities have different number of subjects in our data Additive model: ...
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### DAG: are there situations where adjusting for mediators is reasonable?

One thing about DAGs keeps bugging me - are there situations where adjusting for mediators is reasonable? E.g. consider the experiment below, where a power-calculated sample of subjects participated ...
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### How to adjust for a categorical variable in a way that its levels have equal weight in regression? (predictions are not for the reference category)

I hope I am not asking a stupid question :) Model salary ~ social_club + town Data ...
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### Confusion with adjusting: adding all predictors into one model or running multiple models

I generally understand quite well the idea of adjusting; however, the current study design is killing me. Despite hours and hours of thinking (and my head almost explode), I still don't know, which ...
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### Area and time adjusted counts

In 2019 I went to a site and counted 4 species of birds. The size of the site was 130 hectares and I spent a total of 54 hours counting the birds. The peak counts of the 4 bird species are presented ...
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### P-value correction for multiple testing using huge datasets

First of all I apologize without the question is very basic, I am taking my first steps in data science, statistics and bioinformatics. Data information We are evaluating the correlation (using the ...
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### Not understanding adjusted p values with Holm's method. Highest value in series divided by 1

I'm finding an issue while adjusting p-values with Holm's method I cannot understand. It's not a problem in my actual data, but I would appreciate any help to understand the issue. To show the ...
253 views

### Is there any consensus on adjusting p-values for multiple tests?

I'm confused as to when adjustments for multiple tests need to be used. I'm an undergrad who's familiarising himself with stats, so apologies if my question sounds dumb, but I haven't found any ...
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972 views

### Multiplicity correction when using emtrends to see if slopes are different from 0

I have a relatively straightforward question but I haven't been able to find the answer. Consider this example: ...
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### Can controlling for baseline in a regression with change scores be appropriate? (within-subjects design)

I ran a regression model with a change score (post minus pre manipulation) predicting my dependent variable. Initially, I thought it might be also interesting to control for the baseline score (pre ...
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### When do I have to correct for multiple comparison when computing different mutiple regression models?

I' ve got a problem with my thesis. I use a set of 3 bloodbiomarkers plus age as a covariate to predict Marker of Functional Connectivity on the one hand and Structural Connectivity on the other hand. ...
1k views

### Why match if you have the control data already?

I had a question about matching. I understand the benefits of matching prior to conducting a study due to potential increases in statistical efficiency/ adjustment for confounders. Let's say you're ...
63 views

### Comment on the change in p-value following adjustment for confounders

The Second Australian National Blood Pressure Study (ANBP2) was a prospective, randomised, open-labelled, blinded to endpoint (PROBE) trial of Angiotensin Converting Enzyme (ACE) inhibitors versus ...
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601 views

### Adjust alpha when switching from one-tailed t-test to two-tailed

I started with a hypothesis that says e.g. A is larger than B which would usually call for a one-tailed t-test. But after acquiring the data it turns out that the effect seems to be contrary to my ...
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315 views

### Matthews/Phi Coefficient on a 2x2 Contingency Table with Rare Positives

Suppose I want to measure the degree people like gold versus silver. For the sake of argument, let's say I have a contingency table like so: ...
352 views

### Do I need to correct for p-value when doing repeated ANOVA test?

We are investigating the relationship between smoking status and the hormone level. Smoking status is X(three-level) and the level of the hormones is Y(continuous variable). However, the smoking ...
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### How to adjust a confounder in pre-post analyis

I have a paired-dataset of pre and post-surgery measurements of certain biomarkers. I have done a paired t-test to find if there is a difference in the levels of a biomarker, say x1, before and after ...
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### Unadjusted rates vs. observed rates?

In poisson and negative binomial rate models, should the observed rate be the same as the unadjusted rate (in model with only 1 variable)? Should you report these unadjusted rates from a model with ...
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### 'hold constant' and 'adjust for', do these terms have the same meaning?

In the context of regression, is there a difference between saying you held x constant and saying you adjusted for x? Or are these exactly the same thing? Thank you!
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630 views

### How to adjust P values for several Post Hoc tests

I have several continuous dependent variables x1,x2,x3, and one categorical independent variable x4 with 4 levels, I want to apply ANOVA for each of these dependent variables one by one and then do ...
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### Ideal method for confounder adjustment

I have a fairly large dataset (15,000) in which I assessed the association of a three-level categorical risk factor to the outcome. The outcomes were significantly different for the three levels. ...
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### Multiple minimally sufficient adjustment sets in a Directed Acyclic Graph (DAG): Which unbiased estimate should be presented?

Assume that you want to estimate the effect of $X$ (exposure) on $Y$ (outcome). A common question is: What variables should we adjust for in our model in order to get an unbiased estimate of the ...
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