# logistic regression

1. ### 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...
2. ### 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...
3. ### 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...
4. ### 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...
5. ### 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...
6. ### 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:)
7. ### 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...
8. ### 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...
9. ### 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...
10. ### 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...
11. ### 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...
12. ### 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...
13. ### 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...
14. ### 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)...
15. ### 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...
16. ### 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...
17. ### multinomial logistic regression

hi , i have two questions: 1)- is it adequate to run a multinomial logistic regression test using spss on two categorical variables to test the influence relationship, knowing that data is collected via likert scale items and then computed into 5 classes : example from 5 to 10: weak, from 15...
18. ### Between and within group differences

I am doing a research project on antisocial youth behavior and SES inequality. I am supposed to run two level logistic regression in STATA. There is an advise in conducting this analysis: "Distinguish between school vs within school differences in bullying, and then perform new descriptive...
19. ### [SPSS - post hoc analysis and Logistic regression] When the result don't line up

I'm a medical student doing his research interneship. We're currently investigating if there's a link between motoric and mental outcome and MRI imaging done on neonates. Im wondering if the post-hoc analysis I did in SPSS was the right way to do it. When inserting the data in SPSS, I...
20. ### Standardizing logistic regression betas in NHANES

Hi everyone, New user here. I have a logistic regression problem in which I need to compare beta weights across variables in the analysis. I am using NHANES, which of course has a complex sampling design. Rather than using PROC LOGISTIC in SAS, I had to use PROC SURVEYLOGISTIC. I am aware...