BIOL 437 Week Nine p.2 (Experimental Studies)

Question 1

inclusion criteria

Answer 1

-broad vs. specific

>related to extent of generalization

Question 2

exclusion criteria

Answer 2

• that will help control error

- those with difficulty in complying (ex. alcoholics)

Question 3

sample size calculations

Answer 3

• used to ensure number of participants is adequate to test the specific hypothesis
• formulation of null and 1 or 2 -tailed research hypothesis
• desired level of statistical significance
• use table or formula

Question 4

characterize the cohort

Answer 4

• identify info
• demographics
• variables that may be associated with outcome
• clincial factors
• typically the first table in a final report

Question 5

measure variables

Answer 5

• that may be associated with the outcome
• change during the study
• to assure disease is or is not present at baseline
• measures various predictors of outcomes
• be parsimonious

Question 6

choosing comparision group

Answer 6

• not contaminated by treatment
• ideally ‘blind’
• status quo vs. new treatment

Question 7

assuring compliance

Answer 7

• call day beofre clinical visit
• providing reimbursement
• adhering to intervention protocol
• measuring compliance

Question 8

adhering to intervention protocol

Answer 8

• should be well-tolerated (ex. minimal side effects)

- taking once a day vs. complex schedule

Question 9

selecting patient populaiton compromise between

Answer 9

1. The population most efficeint for answering the clinical question
2. The population best for generalizing the study findings

Question 10

selecting endpoint

Answer 10

-often complicated
-surrogate endpoint
>don’t do death
>useful in randomized controlled trials when the outcome of interest is rare

Question 11

phase 1 trial

Answer 11

• unblinded, uncontrolled study with less than 30 patients
• to determine the safety of a test in humans
• patients often have advanced disease and have tried other options
• often undergo intense monitoring

Question 12

phase ll trial

Answer 12

-relatively small (up to 50) randomized, blinded trials
-test:
>tolerability
>safe dosage
>side effects
>how the body copes with the drug
-what disease it can fight against

Question 13

phase III trial

Answer 13

• much larger (maybe 1000s)
• involve random assigment
• used to evaluate efficacy of new treatment
• different dosages often part of evaluation

Question 14

phase IV trial

Answer 14

• large study conducted after the therapy has been approved by health canada
• asseses rate of serious side effects and explore further uses

Question 15

types of randomized controlled trail

Answer 15

1. Run-in design
2. Factorial design
3. Randomization of matched pairs
4. Group randomization

Question 16

run-in design

Answer 16

• all subjects in cohort placed on placebo
• then those who remain in study are randomly assigned to either treatment or placebo
• limitation: subjects who remain may not reflect the population of interest
• can be useful to minimize bias due to loss to follow-up

Question 17

factorial design

Answer 17

• 2 or more series of treatments are tried in all combinations
• can evaluate efficacy of 2 interventions in a single cohort
• subjects assigned 1 of 4 groups randomly

Question 18

randomization of matched pairs

Answer 18

-comparison group similar in regards to confounding
-more accurate estimates than unmatched
-matched according to confounding
>1 assigned to study
>1 to control

Question 19

groups may involve

Answer 19

• practices
• schools
• hospitals
• communities

Question 20

individuals within a cluster

Answer 20

-likely to be more similar to each other compared to those in other clusters

Question 21

ethical principles

Answer 21

• lead to greater likelihood of benefits
• protect subjects from harm
• ensure people’s time is not wasted
• desire to participate is not frustrated

Question 22

Tuskegee syphillis study

Answer 22

• Black americans
• told being treated but weren’
• no informed consent
• diagnostic lumbar punctures (spinal taps)
• contagious nature never told to families
• found that 20% descrease in life expectancy