Outline the importance of biostatistics as it relates to clinical, medical, and public health issues, and cite examples for each case

I. A study is planned to compare two weight-loss programs in patients who are obese. The first program is based on restricted caloric intake, and the second is based on specific food combinations. The study will involve 20 participants, and each participant will follow each program. The programs will be assigned in random order (i.e., some participants will first follow the restricted-calorie diet and then follow the food-combination diet, whereas others will first follow the food-combination diet and then follow the restricted-calorie diet). The number of pounds lost will be compared between diets. Identify the type of study proposed, and indicate its specific strengths and weaknesses. 

II. An orthopedic surgeon observes that many of his patients coming in for total knee replacement surgery played organized sports before the age of 10. He plans to collect more data on participation in organized sports from four patients undergoing knee replacement surgery and to report the findings. Identify the type of study proposed, and indicate its specific strengths and weaknesses.  

III. Explain your understanding of the following study designs, and cite an example for each type of study. 

Cross-sectional designs

Case-control designs

Cohort study

Randomized study designs

From your perspective, what would explain the conflicting results between different studies of the same disease?