logistic regression

  1. R

    Making sense of the parameter delta in this equation.

    Hello, I was reading this paper about pollen dispersal directionality and I am trying to make sense of the so-called directionality parameter \delta The Statistical Model On pages 4 and 5 they explain their analysis under the section `statistical procedure`. More specifically, in the first...
  2. R

    Making sense of the directionality parameter

    Hello, This post has been cross-posted here. I fail to delete the current post to leave only the other post open. Feel free to delete this post if you can do that. Note: The following greek letters and equations are written in LaTex. I was reading this paper about pollen dispersal...
  3. K

    [SPSS - Logistic Regression] Resolve the linearity of logit assumption

    I am running a logistic regression and my income variable violates the linearity of the logit assumption. It is not negatively effecting the goodness-of-fit statistics. I have transformed the variable into a log but that impacted the constant and made the odds ratio explode. When I square...
  4. D

    Ordinal dependent variable - regression help!

    First of all, I am a complete newbie to stats from a non mathematical background, but I need to analyse survey data for my dissertation! So I have a dependent variable that is ordinal - it's a 5-point likert item (strongly disagree - strongly agree). My independent variables are composite...
  5. V

    Logistic Regression model: a significant predicting variable with low sensitivity?

    Hi fellow forum members! Thank you in advance for your time! I used binary logistics regression (SPSS) to determine the relationship between ambient noise levels (a continuous variable on a logarithmic scale, dB) and a single dichotomous dependent variable ("yes" - 1- for whale positive...
  6. R

    How to compare 2 ORs from different regression models.

    I created a logistic regression model to predict an outcome of depression vs. no depression. There are several variables in the model including gender. I then stratified the population and created 2 logistic regression models (one for women and one for men) because of interactions between gender...
  7. M

    Measurement error in binary outcome variable for a case-control study

    I am currently working on a case-control study on a rare disease using a large patient database. Using conditional logistic regression I will calculate odds ratios for different exposures in cases and controls. The validity of the records for the disease of interest (outcome) is unknown. I...
  8. E

    outcomes of surgery

    Can someone point me into the right direction I have a database of patients who have had surgery which is deemed a success or not(0,1). Each patient has a number of variables under interest before or after a date (1,2) one of 4 types of procedure ( 1,2,3,4) grade of surgeon ( 1,2,3) all of...
  9. T

    Problem using CSLOGISTIC command in SPSS

    I moved this to the SPSS section, for three reasons. (1) SPSS section more appropriate, (2) I got many views here, but not suggestions, (3) I had an insight that is a step toward a solution (but still no solution). The title of my thread in the SPSS section is "Odd warning message from...
  10. A

    Fixed term is “(Intercept)” --Dredge function

    Hi, i'm currently running a glm model in R and have attempted to use the following code: Model: resultsnew<-glm(R0A1~MP_Perc+MPHW_Perc+HW_Perc+YP_Perc+AG_Perc+Shrub_Perc+Dist_CountyRoad+Dist_PrimaryRoad+Dist_SecondaryRoad+Dist_TertFireRoad,data=secondorder,family=binomial("logit"))...
  11. A

    Use of scale () function and conflicting standardized values for fixed effects

    Hi, I'm currently using the scale() function in a glmer model (see below) and I'm having some inconsistencies between my standardized coefficient estimates from SAS and those in R. In SAS, the STDCOEF option in a generalized linear mixed model reports solutions for fixed effects in terms of the...
  12. J

    Logit regression interaction/moderation: what to do about it?

    Hi all! I have a multivariable logit regression model that has two terms showing two-way interaction (the interaction also makes biological sense.) So what am I to do about it? Do I just mention it in my findings? Do I remove one of the variables? (How do I decide which one?) I...
  13. A

    Entering interaction terms

    I am new to this site, but have high hopes that I can find some relief. I have a question regarding entering interaction terms (moderation) in SPSS. Is there a conceptual difference between entering interaction terms and main effects via direct entry (at the same time) vs hierarchically (in...
  14. B

    [Clustered Robust Standard Error] - Custering

    I am investigating the effects of age and exercise in protein expression in mouse motor neurons. I have four groups each with a limited number of measurements associated with it. Group (number of mice) Young (6) Young exercised (3) Old...
  15. L

    Logistic Regression

    Hii! I have some, I guess, pretty basic questions regarding logistic regression. I collected data and my dependent variable is, whether respondents always visit the same store (AVC=0/1). In case, respondents did not always visit the same store (AVC=0), they were asked to provide reasons for...
  16. S

    Is there a need to include fixed effects when assessing multicollinearity VIFs?

    I am currently in the progress of performing multicollinearity diagnostics for a logistic regression model using tolerance and VIF calculations based on recommendations in Allison (2012) (Logistic Regression Using SAS: Theory and Application, Second Edition). In my model I include three sets of...
  17. S

    Is this logit model a multilevel model, and what is the correct way to model it?

    I am analyzing a sample of about 6000 actions carried out by about 500 multinational companies in about 80 countries during a 6 year period. Actions are carried out randomly, and are not longitudinal measurements for the same multinational over time. The actions can be of two types (A or B). My...
  18. K

    Trying to replicate SAS Proc Logistic Code in SPSS or R

    I am an inexperienced user on R and mostly use SPSS for any statistical analysis. Recently I have been working at trying to replicate work done using the SAS PROC LOGISTIC command to create a mortality indicator model. I have tried all the logistic models available in SPSS but cannot get the...
  19. Y

    Confounder analysis for LOGISTIC regression

    Hi there, I have the following situation: I have a logistic regression analysis, in which I have 3 variables: The dependent variable- dichotomous- (complication/no complication). The independent variable- continuous variable- no. of days passed since hospitalization. The confounding...
  20. A

    Which analyzing technique?

    Im currently working on my thesis and I wonder which analysis technique to use. I have 2 dependent variables: voting choice (1 exwtreme left, 2left, 3middle,4 right,5extr right) and political participation devided into formal,informal,new participation and voting yes or no. So formal is on a...