I am fairly new to Statistics. I have a large datatset where N=50,000. I have a dichotomous outcome variable Death (0 = Alive 1 = Die) and a categorical variable Weight (0=Normal 1= Obese 2 = Underweight). I am investigating whether weight contribute to an early death by running a logistic regression. I am wondering whether there is a way to check the lineartiy assumption? The Box-Tidwell test does not provide a p-value in this instance. Any advice will be much appreciated. Many Thanks.