Hi,    Now i try to analyze a data using proc glimmix    dependent variable is binary ( 0, 1) level 1 independent variable is categorial  level 2 independent variable is continous   befor making a multilevel model, i wanna check multicollinearity between independent variables especially, i doubt level2 variables would cause the multicollineariy problem because accroding to corrleation anyalsis i confirmed there is higly correlated among some level2 variables ( r>.8)   in case of level1 i've already done mulicollinearity diagnosis using below syntax   proc reg data=fitness; model Oxygen=RunTime Age Weight RunPulse MaxPulse RestPulse / tol vif collin; run;   but i don't know how to check the multicollinearity between level 2 variables   could i just put the level 2 variables in below regression model statement with other level1 variables?    or is there other syntax for logistic multilevel anaylsis?     if you have an answer, please let me know.     thanks !            ... View more