logistic regression

  1. A

    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...
  2. K

    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...
  3. W

    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...
  4. R

    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)...
  5. K

    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...
  6. K

    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...
  7. stacy

    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...
  8. N

    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...
  9. J

    [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...
  10. J

    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...
  11. B

    What test should I use?

    Hi, I am trying to do a statistical analysis on some data I collected at Uni and I am really confused about which test to use. I applied a range of shear stresses (60s, 140s, 250s, 500s, 1000s, 2000s, 3000s and 4000s) to some cells and then I recorded whether a cell marker was present or not...
  12. B

    Interpreting Odds Ratio after Weight of evidence transformation

    I am doing a logistic modeling with several continuous variables and binary outcome variable. 1- event 0-non event. I did the initial modeling with the variables and then did the Weight of evidence(WOE) transformation for all variables except for 1 variable using ratio of Account good/Account...
  13. S

    [Logistic Analysis] How does SPSS calculate the 0.5 Cut-Point?

    I am interested in determining the classification accuracy of an outcome (binary DV - whether a participant has capacity or not to make a legal decision) based on a continuous variable (score on a cognitive test, i.e., Mini-Mental Status Examination (scores 0-30)). Logistic regression in SPSS...
  14. M

    Logistic regression in SPSS

    I have designed a question and now intend to use SPSS to run regression to analyse the results: My dependent variable is: intention to vote. Yes or No. My independent variables are: a series of question ranked on a scale from strongly disagree to strongly agree. I want to test whether the...
  15. J

    Gravity model

    Hi I am currently writing an assignment regarding a trade model using a gravity equation. The dependent variable in the model is Ln(X) and the non-dependent is both Ln (GDP, distance and so on) AND binary variables. So the question is: can I use SPSS for this kind of modelling or would...
  16. M

    Linear regression vs logistic regression

    I have a time series dataset. The, X (Independent variable) is time and is denoted as 1,2,3,4,5,6..1000.etc Y (Dependent variable ) is a percentage scale as 99%, 98.7%, 96%, 91% ...etc. This is a continuous data set. I have 1000 such data points. The first 700 data points used as training set...
  17. R

    Choosing the Correct Analysis - Comparing Categorical Independent Variables (STATA)

    So I want to compare the rates of infection in patients who received drugs A, B, C, and D. Patients could have received one, two, three, or all four drugs, and they could have been given each at different days during their stay. Infection could have happened before the drug was administered, or...
  18. P

    Adjusting for clustered observations

    Hello, I have collected mortality data and several covariates (data on treatment and vital parameters) from patients in two different hospitals. My goal is to analyse effects of treatments on mortality while adjusting for covariates, and using logistic regression would be my first choice to...
  19. R

    Variable selection in Logistic Regression

    Hello all, I have a query regarding attrition analysis using logistic regression. Say that I calculate the length of stay of an employee in an organization (say 'Tenure') and divide tenure in to 10 buckets . Every employee falls in to any one of these buckets(1 to 10). Say percentage attrition...
  20. R

    Best way to treat integer/float column with null values in logistic regression

    Hi, I was wondering if anyone can assist me with this issue. I am building a logistic regression model to predict purchase or not purchase based on web site behaviour data. One of the factors that I would like to include in the model is the visits to purchase and the days to purchase...