1. 1 A hypothesis is an educated guess about how things work. Most of the time a hypothesis in epidemiology is written like this: "If [Exposure] ___, then [Outcome]____ will happen.“ Your hypothesis should be testable. In other words, you need to be able to measure both “Exposure" and “Outcome." Hypothesis

2. What do we mean when we say that there is an association between an exposure and an outcome? Associated Tied Related Linked Things that are associated are linked in some way that makes them turn up together. 2 Connected

3. Suicide Higher in Areas with Guns Smoking Linked to Youth Eating Disorders Snacks Key to Kids’ TV- Linked Obesity: China Study Family Meals Are Good for Mental Health Students Who Bring Their Lunch to School Eat Less Junk Food Higher Risk of Obesity Among Teens with More Video-Game Playing Breakfast Each Day May Keep Colds Away Study Concludes: Movies Influence Youth Smoking Study Links Iron Deficiency to Math Scores Study Links Physical Fitness to Academic Achievement Proximity of Fast Food Restaurants to Schools and Adolescent Obesity 3

4. 4 When it comes to health-related behaviors, what are you curious about?

5. 5 Rarely or Never Wore a Bicycle Helmet Rarely or Never Wore a Seat Belt Ever Smoked Cigarettes Ever Smoked Cigarettes Daily Ate Fruit or Drank 100% Fruit Juices Two or More Times per Day Ate Vegetables two or more times per Day Did Not Drink Milk Drank Two or More Glasses per Day of Milk Did not Drink Soda or Pop Drank Soda or Pop two or More Times per Day Ate Breakfast on 0 Days Ate Breakfast on All 7 Days Physically Active at Least 60 Minutes per Day on 5 or More Days Participated in Muscle Strengthening Activities on 3 or More Days Used Computers 3 or More Hours per Day Watched Television 3 or More Hours per Day Attended Physical Education Classes Daily Played on at Least One Sports Team Overweight Described Themselves as Overweight Trying to Lose Weight Eight or More Hours of Sleep YRBSS health-related behaviors

6. Eat school cafeteria food Have a sedentary lifestyle Have a high-fat diet Have a low-fat diet Take multivitamins Eat junk food every day Regular family meals Skip lunch Unhealthy snacks Other possible behaviors in a hypothesis Drink high calorie drinks Drink diet soda Drink caffeinated drinks Walk to school Live near a fast-food restaurant Eat at fast food restaurant Fatigue (crash) during day Other ? ? ? 6

7. Parental supervision Texting Computer games Non-health-related factors that may be used as an exposure 7 Television Computer time Seeing films with smokers

8. Eating fruits and vegetables People who rarely watch TV are more likely to eat fruits and vegetables People who eat more fruits and vegetables take more multivitamins Physical Activity Physical activity is associated with a longer night’s sleep People with high academic performance are more likely to also have more physical activity 8 Some variables can be either an exposure or an outcome in the hypothesis

9. 9 “Can we decide on our own hypothesis? Yes, with some guidance: Pick something that your team is genuinely curious about Use correct hypothesis language Be sure it is school appropriate It will be subject to approval by your Principal

10. 10 EPI Challenge Master Proposal Form Name of Team Member ________________

11. 11 Study Proposal: Section 1 Health-Related Behavior and Hypothesis 1a.i. Name a health-related behavior that is of genuine interest to your team and that you would like to study. 1a. ii State why this behavior is of interest to your team. 1.a.iii State why it is a relevant topic to explore in your school.

12. 12 Study Proposal: Section 1 Health-Related Behavior and Hypothesis 1b. State a hypothesis about your health-related behavior that you would like to test. (The hypothesis must be “school appropriate” and will require the approval of your Principal.)