Question

What type of study design was used to compare the risk of self-harm behaviors before and after bariatric surgery (hint: Check out the Study Design section under Methods)? a. Cross Sectional b. Crossover design c. Retrospective d. Case Control 2. What is the alternative hypothesis of the study? a. There is a difference in self-harm behaviors before and after bariatric surgery. b. There is no difference in self-harm behaviors before and after bariatric surgery. c. There is a difference in self-harm incidence between patients with normal and obese BMI. d. There is no difference in self-harm incidence between patients with normal and obese BMI.

Answer 1

Answer: Option b - Crossover design

Study design that was used to compare the risk of self-harm behaviors before and after bariatric surgery is 'Crossover design'. In 'Crossover design' the experimental unit (patient) receives different treatments during the different time periods. In our case study it is the comparison of the risk of self-harm behaviors before and after bariatric surgery.

Answer: Option a - There is a difference in self-harm behaviors before and after bariatric surgery

For the given problem, the null hypothesis is that there is no difference in self-harm behaviors before and after bariatric surgery while the alternative hypothesis of the study is that there is a difference in self-harm behaviors before and after bariatric surgery