• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/19

Click to flip

19 Cards in this Set

  • Front
  • Back
What is the purpose of randomized trials?
To evaluate the effectiveness and side effects of new and established interventions for disease prevention and therapy
What are the 3 essential features of effective studies?
1) controlled
2) randomized
-patients assigned at random to assigned groups
3) Blind, ideally double blind
What does it mean if a study is controlled?
Compare a treated group to a control group who did NOT receive the treatment
What do we mean by a blind or ideally a double- blind study?
Patient and ideally the observer, don't know who is in the treatment group and who is in the control group
What is the basic design of a randomized trial?
Defined population -----> randomized-----> new treatment + current treatment
-New treatment---> improved + not improved
-Current treatment----> improved + not improved
Why should the study population should be defined in writing?
because this is the population you can make inference to in terms of your experimental results
What are the 2 steps to selection of subjects & allocation to treatment group?
1) Defining the study population in writing
2) Randomization
What are 2 methods used to randomize a population when performing randomized trials?
1) Flip a coin
2) Use a random number table
When should the assignment of to control groups and experimental groups be made?
Before seeing the patients or by an outside party (NOT the investigator)
---> assignment of the next patient unpredictable to patient and investigator
What are 2 things that must be considered when examining a control group compared to an experimental group?
Have to consider division by sex and age- were things randomized or is one group more old vs young patients?
What is the definition of internal validity?
Extent to which study results are corrected for sample of patients being studied
What are 3 factors that affect the internal validity of a study?
1) Randomized
2) Controlled
3) Blind
What is the definition of external validity?
Generalizability, the extent to which results of a study can be generalized to the whole population
What question do you need to ask yourself when considering the external validity of a study?
Is the sample of patients in the study REPRESENTATIVE of the patient population as a whole???
What are 7 validity questions you need to ask yourself when examining a study?
1) Is the case definition explicitly, exclusive and uniform?
2) Is a comparison group explicitly identified?
3) Are both treated and control patients selected from the same time and place?
4) Are patients allocated to treatment and control groups w/o bias?
5) Is the intended intervention, and only that intervention, experienced by all of the patients in the treated group and not in the control group?
6) Is the outcome assessed without regard to treatment status
7) Is the method used to determine the significance of the observed results defined explicitly? Can we be certain that the observed results could not have occurred by chance alone?
What is the best approach for evaluating the effectiveness and side effects of disease and interventions?
Randomized trials
What are the 3 things that are essential to ensuring internal validity of a trial?
1) Randomization
2) Controls
2) Blinding
What does the external validity of a study depend on?
The study population being representative of the total population of interest
What is the only way to get conclusive answers?
Performing Experiments