Seroconversion

Seroconversion

by Brian Young -

Hey y'all,

I'm trying to figure out how to do 5j - I've made a variable that is -99 if the patient is HIV + and otherwise is equal to the id number of the patient, which I think is what the hint is suggesting. I'm not sure how this is helpful to me to identify patients who were previously negative and seroconverted as opposed to patients who simply tested positive on their first test. I'm thinking that it has something to do with marking duplicates between this new variable and the patient ID - has anyone had luck with this?

Re: Seroconversion

by Emily Tang -
Hi Brian,

I think for the first part of that problem, we're trying to make a variable indicative of whether a patient is HIV+ or not, which you can use the variable you created from part e. I was also trying to figure out how to distinguish those who changed from negative to positive vs those who were just positive, but I learned in OH that we are disregarding that for this question.

Re: Seroconversion

by Taylor Howell -
For Question 5j, you are asked to generate a variable that indicates whether each participant ever seroconverted during follow-up. One way to do this is to create an indicator for HIV+. In other words, you could make a variable that indicates HIV+ and is otherwise set to missing. Then, you could fill in the missing values with the values that are constant over a unique identifier (see Lecture 4, slide 27). You may then also want to label the new variable.