Chapter 2- Research Methods

Question 1

Prospective Treatment Assignment?

Answer 1

Have some information on the person before we follow them into the future; whether or not the investigator designs the exposure; do they become involved before or after they start their treatment

Question 2

Experimental study

Answer 2

Manipulated treatment variable to follow the effects

Question 3

Observational

Answer 3

Don’t follow the treatment
Don’t intervene or change the participant’s course during the trials
Simply observing them

Question 4

Is there a comparison group?

Answer 4

Yes- Analytical Study
No- Descriptive study

Question 5

Tx → Outcome

Answer 5

Cohort Study
Identify a group that receives a treatment, and following them prospectively to see what the treatment is
Example- using new york state quit line to see who’s trying to quit smoking, and following them for another 6 months to see whether or not they quit and compare them to people who didn’t call the quitline

Question 6

Advantages of Cohort study

Answer 6

Track progress over time
Not relying on people’s memory
Documenting the prevalence of relapses

Question 7

Disadvantages of cohort study

Answer 7

Cannot tell if treatment caused the outcome (no cause and effect)
Are you manipulating the treatment? No → all you are doing is observing and if they are just observing, they are just correlations

Question 8

Tx ← Outcome

Answer 8

Case control study

Question 9

Case control study

Answer 9

Start from the outcome
Example- Find people who quit smoking in the past 6 months and see which people are more likely to call the quitline
Remembering backwards to determine whether or not they had a treatment
Example- someone who developed a disease and looking backward to see if they were exposed to a pathogen

Question 10

Same Time

Answer 10

Cross-Sectional Study

Question 11

Cross-Sectional Study

Answer 11

Most common studies seen
Only doing the survey once, and seeing if that at that moment in time, are the studies correlated
Cannot say that one thing caused/predicted the other
Use one time point to assess both outcome and treatment exposure
Can provide estimates of frequency or prevalence of an outcome or treatment
Can’t tell you which came first
Subject to recall bias

Question 12

Cohort Study Strengths

Answer 12

Treatment comes before outcome (temporal precedence)
Less prone to recall bias
Provides estimates of incidence of outcomes over time

Question 13

Cohort Study Limitations

Answer 13

Cost
Rare outcomes are hard to observe
Studies may need to be very long to observe outcomes

Question 14

Case-Control Study Strengths

Answer 14

Useful for rare outcomes
Can save time and money

Question 15

Case0Control Study Limitations

Answer 15

Difficult to select an appropriate control group
Recall bias
Cannot tell you how prevalent the outcome or treatment is - only the odds of experiencing both
More variables involved - more people might develop that outcome, they just haven’t yet

Question 16

Rate

Answer 16

frequency of an event in the population over a defined period of time

Question 17

Proportion

Answer 17

frequency of an event without a defined time period

Question 18

Ratio

Answer 18

number of people in one condition, relative to the number in another

Question 19

Rate Example

Answer 19

Number of people with depression in the US who saw a therapist last year / Total number of people in the US who had depression last year
Example- Rate of people who have depression seeing a therapist

Question 20

Proportion Example

Answer 20

Number of adults in the US who see a therapist / Total number of adults in the US
More broad

Question 21

Ratio Example

Answer 21

Number of people who attended therapy in 2022 / Number of people who did not attend therapy in 2022

Question 22

Absolute risk = ??

Answer 22

probability of an outcome

Question 23

Absolute risk = ??

Answer 23

probability of an outcome

Question 24

Relative Risk = ??

Answer 24

ratio representing how often the outcome happens in the treatment group, relative to the untreated group

Question 25

Absolute Risk Example

Answer 25

If you attempt to quit smoking, what is the probability that you will relapse?

Question 26

Relative Risk Example

Answer 26

Some treatments show that people are 4x more likely to talk to their doctor about quitting compared to those who didn’t go through the treatment

Question 27

Odd Ratio

Answer 27

Likelihood of membership in one group, given membership in another (also relative)

Question 28

Odd Ratio Example

Answer 28

Example- given membership in the treatment group (vs. non-treatment group), how likely are you to also be in the outcome group Example 2- what are the odds people went on to use additional treatment vs. not

Question 29

Inclusion Criteria

Answer 29

Who gets to be included in the study Define severity (example- diagnosis) Example- can anyone who displays depression symptoms participate or do they have to be clinically defined as being depressed at east 1 month before the study? What works for whom? Question being answered People in the trial define the conclusions you can draw Specific course or duration Consider potential iatrogenic comorbidity Staging and use of adaptive designs

Question 30

Recruitment

Answer 30

How are participants identified? Is the sample representative? If we made compromises, how can we assume scientific studies and draw accurate conclusions

Question 31

No treatment or waitlist

Answer 31

Minimal attention Either receive the smoking intervention or get nothing Problems- People have to believe in the treatment and the placebo effect aids in treatment effect sizes If you have a no treatment group, how much of an impact your intervention had might be artificially inflated because you're not comparing to a placebo effect, you are comparing it to nothing

Question 32

Treatment as usual (control group)

Answer 32

What does someone do when they usually go to the doctor and compare it to whether their treatment works better than medical practice guidelines Challenging to define, and often isn’t homogenous Compared to someone who goes to a clinic and seeing what they get

Question 33

Attention placebo control

Answer 33

Non-specific factors - patient-therapist rapport, contact time with the therapist, BUT no active treatment component Allowing for the possibility of people getting better due to the placebo effect and due to positive patient-therapist rapport

Question 34

Parallel treatment Design

Answer 34

Enrolling 100 people in the study, splitting them and, then observing them at the same time Both groups are going through the same thing at the same time

Question 35

Adaptive Design

Answer 35

Should people get a treatment that is tailored to them, or just a generalized treatment for everyone “Just in time” interventions Someone signs up for the interventions and we identify certain time and situations where they are in a setting and something is pushed to their cell phones to give adaptive content that differ within the group to help them

Question 36

Dismantling Design

Answer 36

What works for whom in what context and why What are the active ingredients of the treatment What pieces of the treatment is causing the effect? Why? Do we need all of it? What treatment components do we keep and what do we try to get rid of

Question 37

Treatment allocation should be blind and concealed from those administering assessment

Answer 37

How do we make these assessments and define our outcomes Who is assessing them

Question 38

Pre and post treatment, consider length of follow up

Answer 38

Short follow up usually Showing something worked before or after Don’t know long term outcomes because its hard to follow people for an extended amount of time

Question 39

Define a priori

Answer 39

Before we started “Moving the goalposts” - say you need to get a certain outcome and you don’t reach it so you just move what the outcome is supposed to be What are the outcomes before you conduct the study? When you report the results, did they actually report the outcomes they said they were going to, or did they move the goalposts? Define level of improvement they consider acceptable

Question 40

What level of improvement will mean the treatment worked?

Answer 40

Remission Reduction of symptoms Longevity of change

Question 41

Efficacy

Answer 41

It worked in a controlled trial If was efficacious Given all the things we just talked about and the randomized control trial was controlled, all the things are super valid in the trial, BUT they could lack generalizability Questions- for whom? Under what context? Often, people who participate in well-controlled, high-validity control trials are a homogenous group that is really different in subsequent ways Valuable in that it tells if things could work and provides the experimental control that allows us to determine cause and effect BUT is extremely limited in how it advises Therapist tape record session and researchers watch to make sure they’re doing what they need to be doing

Question 42

Effectiveness

Answer 42

Have to let go of some of the control Different situations that people use a technique in Need to take efficacious studies and test them for effectiveness

Question 43

Stringent Criteria for study designs

Answer 43

Must have active control, large sample sizes, support from more than one study conducted by different research groups Efficacy? Large control/sample size? Different research groups? Must be able to show different research groups have the same control

Question 44

Subjects to limitations of RCTs

Answer 44

Efficacy vs. effectiveness Manualized interventions

Question 45

Evidence-based Practice

Answer 45

Going straight to the research Look up what research has been done, and what seems to be effective What is efficacious and integrate that with the patient's values and preferences Honest about the goals and treatments going into the therapy Evidence-based practice- Some research/evidence that shows it can be beneficial

Question 46

Evaluating the Evidence base

Answer 46

There will always be strengths and limitations to designs No such thing as a perfect study Must make compromises Making sure to balance strengths and limitations Fallible- must make sure to be flexible Example- PTSD- symptoms may get worse before they get better Possibly shifting the course of treatment after monitoring progress and understanding challenges and limitations that research can provide