Application to Patient Care

Question 1

Internal Validity

Answer 1

Degree that study results are correct for study subjects

Question 2

External Validity

Answer 2

Degree that the study’s conclusions are generalizable to the wider population

Question 3

What influences Validity

Answer 3

The study design influences internal validity
- Can be asking the wrong question resulting in outcomes that can not be applied elsewhere

Question 4

What to do if patient does not fit inclusion/exclusion criteria

Answer 4

Consider how their differences will affect their outcomes and if it matters

Question 5

Limitations of Randomized Trials

Answer 5

Only estimate the average treatment effects
- Not 100% sure that the patient will achieve the same results

Question 6

Post Hoc Study

Answer 6

A subgroup study that aims to look into the data and perform a subgroup analysis

Question 7

Can you trust the results of a subgroup analysis

Answer 7

Generally no
- Subgroup analysis can hide negative results
- These results can be obtained after the study is done to fish for certain results
- Sample size is also smaller and more prone to bias

Question 8

Uses of subgroup analysis

Answer 8

To determine the differences between varying treatment effects
- It is best to declare the subgroups prior to the analysis

If magnitude in difference is large enough than the subgroup analysis can influence treatment

Question 9

Applying a study of one drug to other similar drugs

Answer 9

EBM and Innovators say NO

Insurance Payers and “Me Too” Drug Companies

Question 10

Surrogate vs Patient Important Outcome
- How to determine the difference`

Answer 10

Ask yourself: Can the patient feel the outcome
- If yes then it is patient important
- If no then it is a surrogate marker

Question 11

Issues of using Surrogate Markers

Answer 11

The relationship between the surrogate outcome and the clinical meaningful endpoint is usually unpredictable and inconsistent
- Leads us to make incorrect predictions based on inferences from the surrogate outcome

Question 12

What is a Composite Endpoint

Answer 12

Number of patients experiencing several events

Question 13

Why are Composite Endpoints used

Answer 13

Individually the outcomes would take too long to follow up or require too many patients to observe
- Increases the Event Rate of the outcomes

Question 14

Limitations of Composite Endpoints

Answer 14

Have to ensure treatment affect is the same for each one of the components

Question 15

Considerations of Composite Endpoint

Answer 15

Ensure that it is okay to combine all components and that it makes sense
- One component may be driving the overall composite and making it seem clinically significant

Question 16

Applying Results to Patient Care
- 3 Main Questions

Answer 16

1. Are the study patients similar to my patient
2. Were all clinically important outcomes considered
3. Are the benefits worth the potential harms and cost