Questions tagged [odds-ratio]

A measure of association between two binary variables equal to the odds of a 'positive' outcome in 1 variable divided by the odds in the other. The OR ranges (0, infinity). It has a strong connection to logistic regression.

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Logistic Regression in R (Odds Ratio)

I'm trying to undertake a logistic regression analysis in R. I have attended courses covering this material using STATA. I am finding it very difficult to replicate ...
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Why do my p-values differ between logistic regression output, chi-squared test, and the confidence interval for the OR?

I have built a logistic regression where the outcome variable is being cured after receiving treatment (Cure vs. No Cure). All ...
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Poisson regression to estimate relative risk for binary outcomes

Brief Summary Why is it more common for logistic regression (with odds ratios) to be used in cohort studies with binary outcomes, as opposed to Poisson regression (with relative risks)? Background ...
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Interpretation of simple predictions to odds ratios in logistic regression

I'm somewhat new to using logistic regression, and a bit confused by a discrepancy between my interpretations of the following values which I thought would be the same: exponentiated beta values ...
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Help me understand adjusted odds ratio in logistic regression

I've been having a hard time trying to understand the use of logistic regression in a paper. The paper available here uses logistic regression to predict probability of complications during cataract ...
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logit - interpreting coefficients as probabilities

I seem to be missing some vital piece of information. I am aware that the coefficient of logistic regression are in log(odds), called the logit scale. Therefore to interpret them, ...
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Negative coefficient in ordered logistic regression

Suppose we have the ordinal response $y:\{\text{Bad, Neutral, Good}\} \rightarrow \{1,2,3\}$ and a set of variables $X:=[x_1,x_2,x_3]$ that we think will explain $y$. We then do an ordered logistic ...
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Does it make sense to use Logistic regression with binary outcome and predictor?

I have a binary outcome variable {0,1} and a predictor variable {0,1}. My thoughts are that it doesn't make sense to do logistic unless I include other variables and calculate the odds ratio. With ...
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Why do odds ratios from formula and R's fisher.test differ? Which one should one choose?

In the following example ...
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Calculating risk ratio using odds ratio from logistic regression coefficient

I have a binary logistic regression with just one binary fixed factor predictor. The reason I don't do it as a Chi square or Fisher's exact test is that I also have a number of random factors (there ...
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What is the distribution of OR (odds ratio)?

I have a bunch of articles presenting "OR" with a- 95% CI (confidence intervals). I want to estimate from the articles the P value for the observed OR. For that, I need an assumption regarding the ...
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How do I calculate the standard deviation of the log-odds?

I have in my notes that the standard deviation of log odds is given by the $$\sqrt{(1/a + 1/b + 1/c + 1/d)}$$ I know that the derivation of this requires the Delta Method, but I'm not familiar with ...
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