logistic regression

  1. S

    Is it necessary to check for multicollinearity of explanatory variables in logistic regression?

    Checking for multicollinearity of independent variables is necessary in linear regression since multicollinearity increases the standard error, which in turn affects t-stats and p-values. But in logistic regression, p-values are based on Khi2, therefore multicollinearity has no effect on the...
  2. T

    Logistic Regression Stata: ommitted due to collinearity ?? Help

    Hi there, I'm an MSc student in Medical Entomology and I'm in the midst of analysing data for my final project write up. My project is assessing the efficacy of different insecticide treatments applied in experimental huts against malaria mosquitoes. Now my dependent variables are: mortality...
  3. S

    Logistic Regression vs survival analyses in large cohort studies

    Hello, I was wondering if anyone could give me some advice regarding the right statistical approach for a large cohort. I have a large prospective cohort of ~1.5 million lines of data. It contains people who were assessed as being eligible for an intervention who either went on to have the...
  4. V

    Interpreting Mixed Effect Logistic Regressions with Interaction Effects

    Hello, I need to interpret mixed effect logistic regressions, but I do not quite understand how I can go about doing this when an interaction effect is involved. My main aims involve determining whether metabolic syndrome is associated with decreased mental health-related QoL (low MCS) over...
  5. P

    Logistic Regression Models Without Main Effects?

    Hi there, I am building logistic regression models measuring human behaviour, which consist of categorical variables: demographics, conditions, and interactions between the demographics and the condition variable. The big issue is that as per my theory tested I am not interested at all in the...
  6. S

    Logistic Regression: Estimate

    TestTrans YTrans N TotalRRRR055104.7%50.0%131691005.7%31.0%Total3674
  7. A

    Should i use Multinomial Logistic Regression?

    Hello to all. I have an x-ray evaluation of patients. Each patient was seen in the clinic at different time intervals (Days between xrays), not regular times. There are different rates of application to clinics for patients (at least 3, at most 10 or more times) X-rays were evaluated for a...
  8. C

    Controlling for time

    Hello, Thank-you for taking the time to read this post. I have managed to get myself very confused about what is (hopefully) quite a simple problem. I am aiming to look at the engagement on Twitter during election debates. I have collected tweets and have coded them in regards to their...
  9. D

    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...
  10. S

    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...
  11. I

    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...
  12. P

    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...
  13. rogojel

    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...
  14. B

    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...
  15. B

    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...
  16. A

    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...
  17. A

    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...
  18. P

    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:)
  19. H

    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...
  20. R

    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...