EAB - Part 1 - Statistics in Practice: Senior KCL Biostatisticians describe their Use of Statistical Methods in Clinical Research Flashcards
What do statisticians do?
Statisticians work with clinicians in research to explore and test hypothesis and to validate assumptions using actual data.
Describe randomization in the context of a clinical trial.
It is the random allocation of participants into an experimental group and a control group.
It avoids selection bias.
Successful randomization makes different groups have similar characteristics at baseline.
Describe blinding in the context of a clinical trial.
A blind experiment is an experiment in which information about the test is kept from the participants
The aim is to reduce or eliminate bias. Bias may be intentional or unconscious.
List the different types of blinding in clinical trials, and what they entail.
Unblinded/ open label:
All parties are aware of the treatment allocation.
Single blind/ single-masked:
Participants are unaware of the treatment they receive.
Double blind/ double-masked:
Participants and clinicians / data collectors are unaware of the treatment participants receive.
Triple blind:
Participants, clinicians / data collectors and data analysts are all unaware of the treatment participants receive.
Define un-blinding in the context of clinical trials.
It is the disclosure to participants or study team of which treatment participants received during the trial.
Describe intention to treat (ITT) analysis.
ITT analysis includes every subject who is randomized according to the randomized treatment assignment.
It ignores noncompliance, protocol deviations, withdrawal, and anything that happens after randomization.
ITT analysis maintains prognostic balance generated by randomisation.
Its estimate of treatment effect is generally conservative. A better application of the ITT approach is possible if complete outcome data are available for all randomized subjects.
What analysis can be used to overcome the shortcomings of ITT?
Per protocol analysis.
What is per protocol analysis?
It is an analysis of a subset of the ITT population who completed the study without any major protocol violations.
This gives a more complete picture of the treatment efficacy.
Describe skin prick testing.
It involves a small amount of the allergen being placed onto the skin and then pricking the skin (it does not draw blood).
If the patient is allergic to any of the allergens being tested, a small bump (hive) will develop within 5-15 minutes.
This disappears after about 30 minutes.
