I was in university when the Ontario Health Study began and they were giving out Amazon gift cards for participating so naturally a ton of students signed up. T

I was in university when the Ontario Health Study began and they were giving out Amazon gift cards for participating so naturally a ton of students signed up. They send out questionnaires to participants every few months. https://www.ontariohealthstudy.ca/ https://www.ontariohealthstudy.ca/