I've just done a multivariate regression analysis, using a p-value from bivariate regression analyses of <0.20 as a cut-off to determine which variables will be included in the multivariate model.
I have a total sample of 628 patients, and the crosstabs shows just right. The bivariate regression analyses also seems normal. However, when I try to converge all the eligible variables, the output seems to unrealistic
Here are some additional information on the model:
While it seems that most of the cases were excluded in the analysis, I think this is not the case... The other analyses I performed also showed that a considerable number of observations were observed, but the models still converged well and aligns with the cross-tabulations.
^These are the summary of the model.
Does anyone know what problems may cause the above phenomenon? I have previously tried performing multivariate regression analyses with less sample sizes and more variables, but they all went well. This is the first time I've encountered such a problem.
Thank you very much in advance.