

Ordered logistic regression 

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Hi, I'm quite new to Mplus and I'm trying to conduct an ordered logistic regression on an outcome variable with four groups. I did the same in SPSS before and there I got results in which a reference category was compared to all other categories (i.e. whether an independent variable predicts categorization into group 1 vs. reference group, group 2 vs reference group and group 3 vs reference group). I was expecting the same results in Mplus, but as far as I get it, results show values associated with a >50% of transition from one level to a higher level. I'm actually interested in whether my IVs predict categorization in the reference group or one of the other groups. Is this possible in Mplus? Or am I completely off in my interpretation of the results. I tried using dummy variables in which two groups were compared, but I'm not sure on how to do this as well.. Thanks in advance! 


When you say "an ordered logistic regression on an outcome variable with four groups", I assume you mean that the outcome variable of the logistic regression has four ordered categories. The comparisons you mention sound more like unordered (nominal) logistic regression. The interpretation of ordered logistic regression is described in our new book: http://www.statmodel.com/Mplus_Book.shtml 


Hi Bengt, Thanks for your response. I indeed have an outcome variable with four ordered categories. I was also noticed that the way I want to interpret my results is more in line with nominal logistic regression, but I'm not sure whether that's the best thing to do as my data is ordered. Do you have any suggestions? Thanks again! 


For ordinal outcomes you look at the probability of the highest category versus remaining categories, the 2 highest categories versus remaining categories, etc. Those have the same log odds ratios. See the book for a worked example. 

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