logistic regression

  1. F

    Interpreting Regression Coefficient in Logistic Regression

    Hi there, One question about the interpretation of regressors and their coefficients in multiple regression models. Supposing that I have the following logistic regression Y = a + b1height + b2weight + e where y is either 1 = male or 0 = female h is height g is weight and I estimate my...
  2. I

    dummy variables in logistic regression

    Hello everybody I have a logistic regression: The dependent variable is dichotomous and was measured in four different countries (A, B, C, D) There are several explanatory variables. One of them is the country where the dependent variable was measured. When I use the "country" as...
  3. P

    Logistic regression curve looks like linear regression

    Hi, I performed a linear as well as a logistic regression analysis (both with Matlab) and plotted those. Now the logistic regression curve is very linear and can be described by the same function as the linear regression. I explain the linearity by the fact that it is only a very small fraction...
  4. S

    Logistic Regression, maybe?

    Greeting and many thanks in advance I have been advised to use Logistic Regression to solve the scenario described below. Can anyone confirm that Logistic Regression is the correct statistical methodology? Or provide suggestions for a better methodology? Scenario A test has 20 questions Each...
  5. M

    Repeated measures to predict binary outcome

    I would like to predict outcome of an event based on repeated measures. The problem is the following one: I have 100 patients with measures of a certain feature at different times, but all the patients do not have the same number of measures. The test data has been taken before knowing the...
  6. Y

    Logistic Regression Summary

    I recently finished a course titled Analysis of Categorical Data at my university. I decided to do some write-ups on courses that I finish so that I can recall the material that I had learned during the quarter. If anyone is interested in logistic regression, they can take a look: blog I'd...
  7. T

    Logistic Regression Forecasts are Over-estimated

    Hi all, I have been trying to develop a logistic regression model which predicts future enrollment in part 2 of a required program sequence, based on characteristics displayed in part 1 of the sequence. Some people have missing data points and so some observations are dropped when building the...
  8. 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...
  9. 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...
  10. 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...
  11. 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...
  12. 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...
  13. S

    Logistic Regression: Estimate

    TestTrans YTrans N TotalRRRR055104.7%50.0%131691005.7%31.0%Total3674
  14. 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...
  15. 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...
  16. 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...
  17. 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...
  18. 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...
  19. 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...
  20. 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...