# logistic regression

1. ### Choosing prior for the regression coefficients in the logistic regression

I'm trying to model Bayesian logistic regression model (using JAGS in R) with my dependent variable (status: 0=alive, 1 death) & independent variable (age) in the categorical form (0=patients < 65 yrs old, 1=patients >=65 yrs old). I'm using normal dist. as a prior for constant term, b0 and...
2. ### URGENT! Reviewing SPSS output

Hi guys, I'm needing help with figuring out my results for logistic regression, I have to get this in to my supervisor in 6 hours and I'm freaking out! I'm sure it'd be easy as pie for someone who knows the basics.. I've never been good with statistics, if anyone is willing to help can you...
3. ### STATA Logistic Regression Intepretation

Hi, My dependent variable is goes to college coded 0=No and 1= Yes. I am not sure how STATA reads/ranks the dependent variable....thus I am not sure if I am interpreting correct. Predictor variables overeating status 1=does not overeat (reference) 2=sometimes overeat 3= always overeats and...
4. ### unbalanced design in contingency table analysis. Is it a restriction?

I conducted a research in to elucidate the biology a of an insect seed predator that infest seeds of a palm specie in cloud forest in Venezuela. I did collected seeds directly from the palm and seeds picked up from the forest floor in two localities. I want to know if differences exists between...
5. ### Simulating a logistic regressio - scary results

Hi, I tried to work out the necessary sample size for a logistic regression by simulations and got some scary results. If anyone could check the code below, it would be a great help. I simulate a logistic regression with two normalized variables, one having a fixed odds ratio of 1.4 the other a...
6. ### SPSS Complex Samples Logistic Regression

Hi all, I am hoping this is a simple question... I am using SPSS for complex samples and in my logistic regression output I do not have any p-values for the significance of my variables. Does anyone know where I can get the p-values in my output of logistic regression of complex...
7. ### Logistic regression : negative coefficients, categorical variables

Hi I am trying to build attrition model and have these variables :- 10 categorical variables with sub levels which created into dummy variables and 4 continuous variables in a trained data set. My Y dependent variable is binary variable. After running log regress, the results are some of the...
8. ### External validation of a log reg model using Nagelkerkes R2 w/ fixed parameters

I have a dataset containing a point score (an integer between 0-41) and mortality (0/1) for a sample. I have performed a logistic regression analysis on these data (mortality~score) and extracted the parameter estimates (intercept and regression coefficient for the point score), and have used...
9. ### Logistic regression - intepretation of results

Hi all, I have binary data for which 70% involve 1 (yes) and 30% involve 0 (no). I've done logistic regression in MedCalc. Results below: Sample size 60 Positive cases a 42 (70,00%) Negative cases b 18 (30,00%) a Bacteria = 1 b Bacteria = 0 Overall Model Fit Null model -2 Log...
10. ### logistic regression and ordinal logistic regression

Hi, I am currently studying the ordinal logistic regression. I want to ask: is there a relationship between logistic regression with logistic ordinal regression? What distinguishes both of these things? thank you:)
11. ### Help with confirming what I can and cannot conclude from this regression output

This study tried to determine the factors influencing the probability that voters would be asked to show ID in order to vote in a certain state during a certain election. (Model 1 identified Hispanics by self-identification and Model 2 identified Hispanics by whether they had an Hispanic...
12. ### Exp(B) or CI values with the letter "E"

Dear all, I am running a Multinomial Log. Regression. Everything seems fine but I do not understand when Exp(B) oder CI values are like 1,000E-013. I see this result although, the goodness of fit of the overall model is appropriate. For example in: B=-107,4, p=0,031 Exp(B)=1,000E-13...
13. ### Comparing Groups in Ordinal Logistic Regression

Hi, I seem to have gotten a little confused about the possibility of comparing groups in ordinal logistic regression. Here is my issue: I gave people one of three framing conditions for the goal of a task, which varied in the wording of how the goal was presented. Then I let people perform...
14. ### Data input- ordered logistic regression

Hello, I am trying to analyze the relationship between mode familiarity and Technology & demographic characteristics. So I have an ordinal dependent variable and binary, ordinal, continuous and nominal variable as independent variables. My output variable is the familiarity of mode: very...
15. ### Logistic Regression - Predicted Probabilities with unknown variables

Hi all, I'm wondering about how to calculate predicted probabilities using a binary logistic regression model when one or more of the variables in the model is unknown. For example, say I built a model to determine whether or not someone will own a car which uses the following: - Age...
16. ### Calculating predicted probabilities from a logistic regression model SPSS

Hello everyone, I am trying to calculate individual predicted probabilities from a logistic regression model with SPSS (to describe how a individual probability could be calculated from my model in an article). I was looking for a formula how the predicted probabilities in SPSS are calculated...
17. ### R - Logistic regression. Coding to get all predictor variables for categorical vars

I'll preface my question by stating that I am new to using R. I am trying to use logistic regression on my data. I typed glm(formula = purchase ~ predictor vars separated by + sign, family=binomial, data=modeldata) The solution does not produce the multiple intercept and beta coefficients for...
18. ### Comparison of one outcome to all the other outcomes

Here is some data to play with set.seed(1e4) color = factor(c(rep("blue",20), rep("red",20), rep("yellow",150)), levels=c("red","blue","yellow")) x1 = rnorm(20+20+150,12,3) x2 = c(rnorm(20,5), rnorm(20,5), rnorm(150,7)) x3 = c(rnorm(20,7), rnorm(20,5)...
19. ### Multicollinearity problem in binary logistic regression

I'd like to ask for some help with a binary logistic regression. In SPSS I am trying to build a binary logistic regression with 4 independent continuous variables (Sample size - 85). I have a dichotomous dependent variable (a clinical form of multiple sclerosis) and quite a few independent...
20. ### Large odds ratio in binary logistic regression/big scale difference of variables

I'd like to ask for some help with a binary logistic regression. In SPSS I am building a binary logistic regression with 4 independent continuous variables(Sample size - 85). However, with one of the variables (Bicaudatus_index) I get a huge odds radio: I think that I know where the problem...