# Questions tagged [logistic]

Refers generally to statistical procedures that utilize the logistic function, most commonly various forms of logistic regression

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### Estimating logistic regression coefficients in a case-control design when the outcome variable is not case/control status

Consider sampling data from a population of size $N$ in the following way: For $k=1, ..., N$ Observe individual $k$'s "disease" status If they have the disease, include them in the sample with ...
1 vote
170 views

### How to fit a logistic regression for 1 dependent variable and 1 qualitative variable measured twice

I am struggling to fit a simple logistic regression for one dependent value (group) by one independent qualitative variable (dilat) measured twice independently (rater). I try many solutions and ...
456 views

### Is there overfitting in my modelling approach despite cross-vaidation?

My model is predicting a binomial dependent variable with a rich feature space of 20,000 independent variables. I am using the penalized logistic regression from the glmnet package, which works for ...
133 views

### What does a huge gap between P values of the same predictor computed in bootstrapped and non-bootstrapped versions of the same regression mean?

My binary logistic regression gives P values significant at 0.05 level for some of the modeled independent variables. However, bootstrapping the same regression model gives P values significant at 0....
2k views

### Number of levels in categorical predictors/combining categories in logistic regression

I have an independent variable “State in the US” and it has around 16 different levels (PA, NY, NJ, etc). Now I have combined the states which appear infrequently into "others" category. But I still ...
1k views

### Logistic Regression/Naive Bayes with highly correlated data

Background: We work with data from sports event, more accurately with data about the spectators of sports events: how many people are being violent, what kind of event is this, etc. We have quite a ...
10k views

### Interpreting Intercept when doing logistic regression with categorical data in R

In R I have a categorical variable that I performed logistic regression on and got the following result: ...
547 views

### Application of Logistic Regression

I have the following data set: ...
2k views

### Inclusion of significant interaction term in logistic regression table versus stratification for data presentation

This is a general question on logistic regression result reporting for a publication. We have an example where two well correlated ($r=0.4, p=0.001$) blood parameters (...
1 vote
873 views

### Overlap between robust glm and weighted glm in R

I sometimes have to vectorise the Huber weights from a robust regression and use them in a lm. Recently I've had to do something similar for a logistic model but I'm slightly worried because I don't ...
12k views

### Odds and odds ratios in logistic regression

I am having difficulties understanding one logistic regression explanation. The logistic regression is between temperature and fish which die or do not die. The slope of a logistic regression is 1....
4k views

### Relationship between McNemar's test and conditional logistic regression

I am interested in the modeling of binary response data in paired observations. We aim to make inference about the effectiveness of a pre-post intervention in a group, potentially adjusting for ...
260 views

### Counterpart to regression equivariance in logistic regression?

Let $T(y_i,\pmb x_i)$ be a regression estimator (of the scalar $y_i$ unto the $p$-vector $\pmb x_i$). When $T$ is the usual LS estimator and $\nu\in\mathbb{R}^p$, we have that: T(y_i+\pmb x_i'\pmb\...
11k views

### Appropriate regression model when dependent variable is between 0 and 1?

I am performing a regression where my dependent variable is the value of a group's Simpson Diversity Index. This index value is constrained by $1/k$ and $1$ (where $k$ is the number of classes), ...
757 views

### Statistical Analysis on mostly boolean values

So I have a large dataset, and I was wondering what the best way to conduct statistical analysis of it is. I'm very green in terms of statistical methods, but I learn quickly. Basically, each item has ...
7k views

### Investigating robustness of logistic regression against violation of linearity of logit

I am conducting a logistic regression with a binary outcome (start and not start). My mix of predictors are all either continuous or dichotomous variables. Using the Box-Tidwell approach, one of my ...
1k views

### Stepwise versus L2 regularized logistic regression: dataset-specific performance

I have two data sets from different collections. The second data set is smaller. They were both analyzed with the same methods in order to derive feature sets of 10-30 features each. Each feature set ...
14k views

### Calculating ICC for random-effects logistic regression

I'm running a logistic regression model in the form: lmer(response~1+(1|site), family=binomial, REML = FALSE) Normally I would calculate the ICC from the ...
6k views

### Correlation between discrete and continuous variables

I am using a scale which consists of discrete values 0 (normal), 1 (mild), 2 (moderate), 3 (severe). I have used this scale for 200 patients. I am going to find the correlation of this scale with ...
2k views

### Is it technically "valid" to fit a logistic regression with a dependent variable that is a proportion?

Several posts (here and here) suggest that beta regression is more appropriate when the dependent variable is naturally bounded between 0 and 1. My question is, leaving appropriateness aside, is it ... 2k views

### Do the commands logit and glm (Binomial family) in Stata use different fitting/estimation algorithm?

In my mind, the commands logit and glm (Binomial family) in Stata both use maximum ...
1k views

### Multiple testing and logistic regression

I want to perform a number of univariate regressions with different symptoms (e.g. fever, cough, sneezing) as the response variable and one categorical variable (which is always the same each time) as ...
1k views

### Adding variables to the model one by one, or at the same time

What are the benefits of adding the variables into a model one by one, as compared to adding them all at the same time? As I see in most research, the first model that is tested is consisted of all ...
498 views

### Fractional Polynomial interpreting interaction terms

Background: I have developed a logistic regression model where I am trying to analyze the effect of socio-economic data of a family on their probability of receiving a home loan. I have used ...
749 views

### Less significant findings using conditional logistic regression

I used regular logistic regression on my dataset and got a few significant hits. However, since the data is 1:1 case-control matched data I decided to try using conditional logistic regression (...
521 views

### (Why) should bootstrap sampling distribution for logistic regression slope be conditional on $S=\sum Y_j$?

I am working my way through Chapter 4 (Tests) in Davison & Hinkley's (D&H's) book "Bootstrap Methods and their Applications", and have a question about one of their examples. Davison & ...
11k views

### Conditional logistic regression vs GLMM in R

I have paired data (GWAS case/control study) and I have heard using conditional logistic regression or generalized linear mixed models (GLMM) is appropriate. Which should I use in this case? Why would ...
3k views

### Simulate data for power analysis of logistic regression model - include covariance variance of variables?

I've tried to simulate data for a power analysis of a logistic regression. The results of the power analysis look reasonable: power=90% for a sample of 6000 persons. But I feel that the analysis lacks ...
377 views

### Separation in logistic regression in a complex survey?

Firth's penalized maximum likelihood estimates, exact logistic regression and Bayesian logistic regression (e.g. bayesglm) can account for separation in logistic regression. But how to account for ...
362 views

### Goodness of fit vs. significance

If you had two models - one with a better fit, and one with predictors of higher significance - which one would you choose? Keep in mind that both models are considered a good fit. One has a 3% ...
1 vote
4k views

### Nested Logit model in r

I am trying to run a nested logit using mlogit in R to analyze data from choices people made. There are 4 possible alternatives they could choose from, but in any given choice situation a person had ...
1k views

### Multinomial Logit with mlogit and Yogurt Data

I am using the mlogit package in R to estimate a choice model, I started with the famous Yogurt dataset. ...
1 vote
979 views

### When to use ridge estimator / naive Bayes

I used the Logistic function in weka, to predict a binary class. I have used SimpleLogistic before, but Logistic also seem to give me good results. I did want to clarify if I understand some things ...
2k views

### Large scale Cox regression with R (Big Data)

I am trying to run a Cox regression on a sample 2,000,000 row dataset as follows using only R. This is a direct translation of a PHREG in SAS. The sample is representative of the structure of the ...
3k views

### Which is applicable, ordinal or multinomial regression model?

I have done a job satisfaction survey where the DV is a 7 point Likert type scale and 5 IVs with 6 point Likert-type scale and 6 IVs with 5 point Likert type scale, all ordinal. Which type of ...
2k views

### Singularity issues in multinomial logit model with differing choice sets

I am estimating a discrete choice model in which individuals choose which schools to attend. I have a large amount of data on individuals and schools. However, each particular school only appears in ...
412 views

### What value is conditional logistic regression if two cohorts are already matched on everything of interest?

My situation is this: I am comparing two cohorts I have matched the two cohorts on all of the factors that I am interested in The two cohorts are already balanced on all of the factors that I would ...
515 views

### Given the below dependent variable description, should I choose either Ordered or Multinomial logistic regressions?

My dependent variable looks like a range of ranks. It actually might be considered that way. But the ranking is based on subjective non-quantifiable cutoffs. We assessed the behaviors of a group of ...
89 views

### Looking for a regression model or other statistics models for competitions

We have botanical data and need to analyze this sort of scenario, in terms of students for the simplicity of explanation: We have a series of competitions or trials, each one involves two individuals ...
1 vote
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### explaining an extremely large coefficient in a rare events logistic regression

I am running a rare events logistic regression on a binary dependent variable. I have 538 observations and only 10 events (so 528 values of 0 and 10 of 1), which is why I chose to use a rare events ...
636 views

### Power analysis for minimum sample size for 6 continuous predictors and 1 dichotomous criterion

My study has 6 continuous predictor variables and a dichotomous criterion variable. The IRB wants me to provide a power analysis, which I take to mean how I decided on number of participants to ...
1 vote
185 views

### Which machine learning algorithm should I use?

I have one dependent binary categorical variable, and one independent continuous variable. There is a lot of randomness deciding the result of the dependent variable. The relationship between the ...
811 views

### Why do Minitab and SPSS give opposite results in Ordinal Logistic Regression?

I run an ordinal logistic regression model using both SPSS and Minitab. The dataset is exactly the same. The results are exactly the same, but in opposite directions. I have not manipulated default ...
608 views

### Transforming a continuous covariate into a discrete one in logistic regression [duplicate]

I am largely inexperienced in the area of logistic regression. I was wondering if there were a good way to transform a continuous covariate in a logistic regression into a discrete one by subdividing ...
6k views

### Getting the bootstrap-validated AUC in R

In a paper by Faraklas et al, the researchers create a Necrotizing Soft-Tissue Infection Mortality Risk Calculator. They use logistic regression to create a model with mortality from necrotizing soft-...
1k views

### Logistic regression, "sum" confidence interval

I have an existing fitted logit regression model. Model: $\hat{p}(x)=\frac{1}{1+e^{-\hat{\beta}x}}$ With parameter estimates $\hat{\beta}$, and observation $x$ Given a new set of datapoints \$x_1,\...
1 vote
511 views

### Base category and conditional logit coefficients in the multinomial logit model

Why do we need to use a base category (normalised to zero) when working with multinomial logit models? Why do we need to report conditional logit coefficients? Wouldn't marginal effects give us a ...