DrugEpi 3-4 An observational Study of a Natural Experiment: Sensation-Seeking Module 3 Introduction Content Area: Analytical Epidemiology Essential Question

DrugEpi 3-4 An observational Study of a Natural Experiment: Sensation-Seeking

Module 3 IntroductionContent Area: Analytical EpidemiologyEssential Question (Generic): Is there an association between the hypothesized cause and the disease?Essential Question (Drug Abuse Specific): Is there an association between the hypothesized cause and drug use?Enduring Epidemiological Understanding: Causal hypotheses can be tested by observing exposures and diseases of people as they go about their daily lives. Information from these observational studies can be used to make and compare rates and identify associations.

Synopsis

In Module 3, students explore how hypotheses are tested epidemiologically. Students begin to uncover and develop the following epidemiological concepts and skills: the meaning of the term “association;” the need for a control group; uses of the 2x2 table in calculating risks and relative risks; experimental study design; the importance of ethics in human research; observational study designs used in epidemiology; and the strengths and limitations of each design.

Lesson 3-1: Associations and the 2x2 TableLesson 3-2: Experimental Study - Buprenorphine ExampleLesson 3-3: An Actual Randomized Controlled TrialLesson 3-4: Observational Studies of Natural Experiments - Sensation-Seeking ExampleLesson 3-5: Fundamentals of Study DesignLesson 3-6: Study Design Exercises


Module 3 - Analytical Epidemiology

Lesson 3-4 Sensation-Seeking

Content

• Description of natural experiments and the need for observational studies • Demonstration of how the 2x2 table is also used to study associations in

observational studies• Use of “sensation-seeking” as a characteristic that may predict high risk behaviors• Repeated calculations of relative risks to test hypotheses about the relationships

between sensation-seeking and various behaviors

Big Ideas

• By necessity, factors that are hypothesized to be harmful can only be studied in humans by taking advantage of natural experiments and performing observational studies

• The community is the epidemiologist’s laboratory• A measure of “sensation-seeking” in individuals can be scored by answering a set

of questions that ask people to choose preferred situations and activities• In a group study, the degree of sensation seeking is likely to be associated with

the degree of risk-taking behaviorsThis project is supported by a Science Education Drug Abuse Partnership Award, Grant Number 1R24DA016357-01,

from the National Institute on Drug Abuse, National Institutes of Health.


1. How is this disease distributed?

Health-related conditions and behaviors are not distributed uniformly in a population. They have unique distributions that can be described by how they are distributed in terms of person, place, and time.

2. What hypotheses might explain the distribution of disease?

Clues for formulating hypotheses can be found by observing the way a health-related condition or behavior is distributed in a population.

3. Is there an association between the hypothesized cause and the disease?

Causal hypotheses can be tested by observing exposures and diseases of people as they go about their daily lives. Information from these observational studies can be used to make and compare rates and identify associations.

4. Is the association causal?

Causation is only one explanation for an association between an exposure and a disease. Because observational studies are complicated by factors not controlled by the observer, other explanations also must be considered.

5. What should be done when preventable causes of disease are found?

Policy decisions are based on more than the scientific evidence. Because of competing values - social, economic, ethical, environmental, cultural, and political factors may also be considered.

Essential Questions Enduring Understandings

Where are we?


Laboratory


Epidemiologists’ Laboratory


Our Epidemiology Laboratory


An epidemiologic experiment in which subjects are assigned into groups to receive or not receive

a hypothesized beneficial intervention.

Review - Controlled Trial


We conducted a randomized, placebo controlled, multi-center trial to evaluate the safety and efficacy of a sublingual-tablet

formulation of buprenorphine and naloxone in an office-based setting.

Review - Controlled Trial


Total

Tested Negative for Heroin

Tested Positive for

Heroin

Tested Risk of NOT

Using Heroin

Relative Risk

Review: Testing a Hypothesis that a drug regimen will stop heroin addicts from using heroin.

Urine tests were opiate negative 3.6 times as frequently in the Buprenorphine group compared to the placebo group

Bupe &

Naloxone

Bupe

Placebo

109

105

109

17.8%

20.7 %

5.8%

3.6

3.1

Urine tests were opiate negative 3.1 times as frequently in the combination group compared to the placebo group


Naturally occurring circumstances in which groups of people within a population have been exposed to different levels of the hypothesized cause of an

outcome.

Natural Experiment


An epidemiologic study of a natural experiment in which the investigator is not involved in the intervention other than to record, classify, count,

and statistically analyze results.

Observational Study


Naturally occurring circumstances in which groups of people within a population have been exposed to different levels of the hypothesized cause of an

outcome.

Observational Study of a Natural Experiment

Epidemiologic studies of natural experiments in which the investigator is not involved in the

intervention other than to record, classify, count, and statistically analyze results.


Sensation Seeking

A person’s search for an optimal level of arousal or stimulus.

Exposure


Exposure

Low

Sensation Seekers

High

Sensation Seekers


Sensation Seeking

Low

Sensation Seekers

High

Sensation Seekers


Sensation Seeking

Low

Sensation Seekers

High

Sensation Seekers


Sensation Seeking

Low

Sensation Seekers

High

Sensation Seekers


Sensation Seeking

HSS TV Shows

LSS TV Shows


http://www.bbc.co.uk/science/humanbody/mind/surveys/sensation/index.shtml

Sensation Seeking Scale


Brief Sensation Seeking Scale



8 Items

Strongly Disagree

Strongly Disagree

Neither Disagree

Nor Disagree

Strongly Agree

Strongly Agree

1 2 3 4 5

5-Point Scale



8 - 40

25



1. I would like to explore strange places.

2. I would like to take off on a trip with no pre-planned routes or timetables.

3. I get restless when I spend too much time at home.

4. I prefer friends who are excitingly unpredictable.

5. I like to do frightening things.

6. I would like to try bungee jumping.

7. I like wild parties.

8. I would love to have new and exciting experiences, even if they are illegal.

Strongly Disagree

Strongly Disagree

Neither Disagree

Nor Disagree

Strongly Agree

Strongly Agree

1 2 3 4 5


Rules for Filling out the Brief Sensation Seeking Scale

If you do not wish to participate, do not.

Rules

Do not look at anyone else’s paper.

Do not write your name on the sheet of paper.

Fold your paper in half as soon as you are done.


Time to Fill Out the Scale


Rules





What do we mean when we say that there is an association between two things?

Associated

Tied Related

Linked

Things that are associatedare linked in some way that makes them

turn up together.

Review - Things That Turn Up Together


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

Lack of High School Diploma Tied to US Death

Rate

Study Links

Spanking to

Aggression

Breakfast Each Day May Keep Colds Away

Study Concludes: Movies Influence

Youth Smoking

Study Links Iron

Deficiency to Math

Scores

Kids Who Watch R-Rated Movies More Likely to Drink, Smoke

Pollution Linked with Birth Defects in US Study

Depressed Teens More Likely to Smoke

High Sensation Seeking

Is Linked To ?________________?

Things That Turn Up Together


High Sensation Seeking Is Linked to __________________




Low Sensation Seeking



Exposure




Outcome



Outcome

No Outcome



5-Point Scale

Strongly Disagree

Strongly Disagree

Neither Disagree

Nor Disagree

Strongly Agree

Strongly Agree

1 2 3 4 5

Range: 8 - 40

HSS

24 to 40

LSS

8 to 23


Quick Review

How are we determining groups of LSS and HSS?

Assignment?

Naturally Occurring?


Groups of HSS and LSS Students

Step 1: Collect all folded sheets and put into large

envelopes

Step 1: Collect all folded sheets and put into large

envelopes

Step 2: Count the numbers of students in the LSS and HSS

groups


Groups of HSS and LSS Students

LSS HSS

HSS

24 to 40

LSS

8 to 23



XX






OutcomeNo

Outcome Total






OutcomeNo

Outcome Total

a b

c d


a b

c d



Total




a b

c d



Watches TV Show

Does Not Watch TV Show Total


Conducting an Observational “Study” in Class


2x2 Table Worksheet - Enter Study # 1


2x2 Table Worksheet




Do not label the 2x2 table.

Only place 1 check in the appropriate 2x2 table.


Rules

Place a check in 2x2 table

for Study # 1


Collect


High Sensation Seeking Score 24 to 40

Low Sensation Seeking Score8 to 23

a b c d

2x2 Table Worksheet


Sort


Count


Study # 1

Sort

Enter

Count

Collect


a b

c d



Watches TV Show



1


a b

c d



Watches TV Show



or

or

Risk of Watching

TV Show

%

%

1


a b

c d



Watches TV Show



High sensation seekers were ___ times as likely to watch __________ compared to low sensation

seekers.

Relative Risk

or

or

Risk of Watching TV Show

%

%

1


1 None Exposure is not associated with the outcome.

Greater than 1 (>1)

Positive Exposure is associated with a greater likelihood

of the outcome.

Less than 1 (<1)

Negative Exposure is associated with a lower likelihood

of the outcome.

AssociationRelative Risk Interpretation

Relative Risk

Relative Risk: The ratio of the risk of an outcome among the exposed to the risk of the outcome among the unexposed.


Sensation Seeking – Study # 2

High Sensation Seeking Is Associated with __________________


a b

c d



Yes – bungee jumping

No – bungee jumping Total Relative Risk

or

or

Risk of XXXXX

%

%

1

High sensation seekers were ___ times as likely to _______________ compared to low sensation seekers.

Study # 2

2


Study # 2

Re-Distribute the 2x2 Table Worksheets


Study # 2

Sort

Enter

Count

Collect

Place a check in 2x2 table 2


a b

c d




Yes – bungee jumping Total Relative Risk

or

or

Risk of XXXXX

%

%

1


Study # 2

2


A hypothesis can be tested by comparing the frequency of

an outcome in selected groups of people with and without an exposure

to determine if the exposure and the outcome are associated.

Big Epidemiological Idea


Sensation Seeking – More Studies

High Sensation Seeking Is Associated with __________________


a b

c d




No – bungee jumping Total Relative Risk

or

or

Risk of XXXXX

%

%

1


Study # X

X


Study # X

Re-Distribute the 2x2 Table Worksheets


Study # X

Sort

Enter

Count

Collect

Place a check in 2x2 table X


a b

c d




Yes – bungee jumping Total Relative Risk

or

or

Risk of XXXXX

%

%

1


Study # X

X


… and the application of this study to the control of health problems.


Big Ideas in this Lesson (3-4)

• By necessity, factors that are hypothesized to be harmful can

only be studied in humans by taking advantage of natural experiments

and performing observational studies• The community is the epidemiologist’s laboratory• A measure of “sensation-seeking” in individuals can be scored by answering a set of questions that ask people to choose preferred situations and activities• In a group study, the degree of sensation seeking is likely to be associated with the degree of risk-taking

behaviorsThis project is supported by a Science Education Drug Abuse Partnership Award, Grant Number 1R24DA016357-01,

from the National Institute on Drug Abuse, National Institutes of Health.

Re-Cap


6.

Where are we?Next Lesson

Controlled Trial

Cohort StudyCase-Control Cross-Sectional

Observational

Experimental

Study Designs in EpidemiologyStudy Designs in Epidemiology

Documents

DrugEpi 3-4 An observational Study of a Natural Experiment: Sensation-Seeking Module 3 Introduction Content Area: Analytical Epidemiology Essential Question