In the context of clinical trials what is meant by the following terms:
a) Stratification. (20% marks)
b) Intention to treat analysis. (20% marks)
c) Sensitivity analysis. (20% marks)
d) Kaplan-Meir curve. (20% marks)
e) Analysis of competing risk. (20% marks)
a) Stratification of clinical trials is the partitioning of subjects and results by a factor other than the treatment given
b) Intention to treat analysis is the analysis of all participants allocated to a treatment group irrespective of whether they completed the treatment, withdrew, or deviated from protocol.
c) A sensitivity analysis is the analysis of data from the trial with a change or alteration to one or more underlying assumptions used in the original analysis.
d) A Kaplan-Meir curve is a plot of probability of survival against time.
e) Analysis of competing risk is used when there are multiple endpoints of which the occurrence of one prevents the occurrence of another (e.g. death prevents the occurrence of shock reversal
"Stratification is a process that protects against imbalance in prognostic factors that are present at the time of randomisation.
A separate randomisation list is generated for each prognostic subgroup. Usually limited to 2-3 variables because of increasing complexity with more variables"
Intention to treat analysis
"Kaplan-Meir" curve (it's usually spelled "Meier", after Paul Meier):
Analysis of competing risk:
Morris, Tim P., Brennan C. Kahan, and Ian R. White. "Choosing sensitivity analyses for randomised trials: principles." BMC medical research methodology 14.1 (2014): 11.
Rich, Jason T., et al. "A practical guide to understanding Kaplan-Meier curves." Otolaryngology—Head and Neck Surgery 143.3 (2010): 331-336.
Noordzij, Marlies, et al. "When do we need competing risks methods for survival analysis in nephrology?." Nephrology Dialysis Transplantation 28.11 (2013): 2670-2677.