stata outcome must be 0 or 1

In Stata, if you are working with a binary outcome variable (i.e., a variable that can only take on two values, such as 0 or 1), you should make sure that your variable is coded as such. This means that the variable should have a value of 0 for one category and a value of 1 for the other category.

You can check the coding of your binary outcome variable by using the `tab` command in Stata. For example, if your binary outcome variable is called `outcome`, you can type the following command:

tab outcome

This command will display a frequency table of the `outcome` variable, which should show you how many observations have a value of 0 and how many have a value of 1. If your variable is not coded as 0 or 1, you can use the `recode` command to recode it. For example, if your variable has a value of 2 for one category and a value of 3 for the other category, you can use the following command:

recode outcome (2=0) (3=1)

This command will change all values of 2 to 0 and all values of 3 to 1 in the `outcome` variable.