SFP Flashcards
Definition of funnel plot
a scatterplot of treatment effect (e.g. OR on x axis) against a measure of study precision (e.g. SEM on y axis)
Definition of forest plot
graphical display of estimated results from a number of scientific studies addressing the same question
Definition of standard deviation
measure of amount of variation or dispersion of a set of values
Definition of per-protocol analysis
only subjects who completed the entire protocol are included in the analysis of a randomised clinical trial
Definition of intention to treat analysis:
all subjects randomised are included in the analysis regardless of whether they completed the study
Definition of clinical equipoise
state of genuine uncertainty on relative value of two interventions being compared in a trial
Definition of MHRA Yellow Card scheme
provides early warning that safety of a medicine or medical device may require further investigation
Definition of standard error
SD / square root of (N)
Definition of null hypothesis
hypothesis that there is no significant difference between specified populations
Definition of type I error
falsely rejecting a null hypothesis that is true in the population
Definition of type II error
failing to reject null hypothesis that is false in the population
Definition of power
probability of picking up a significant difference, if there is one
1 – probability of Type II error
Definition of p-value
probability of event happening by chance = wrongful rejection of the null hypothesis = type 1 error
Definition of confidence interval
range within which the true answer will lie 95% of the time
Definition of a priori
pre-specifying end-points & outcomes of a study to reduce reporting bias
Definition of surrogate endpoint
variable relatively easily measured that predicts a distant outcome of the intervention being tested
Definition of composite outcome
combination of two or more outcomes into single endpoint
Definition of Cohen’s kappa coefficient
statistic used to measure inter-rater reliability for qualitative variables
Definition of confounder
variable that influences both exposure & outcome in triangular fashion, causing a spurious association not demonstrating causality
Definition of selection bias
systematic differences between baseline characteristics of groups due to selective recruitment
Definition of performance bias
systematic differences in care provided to different study groups other than the intervention of interest
Definition of detection bias
systematic differences between groups in how outcomes are determined
Definition of recall bias
systematic error that occurs when participants do not remember previous events or experiences accurately or omit details
Definition of attrition bias
type of selection bias due to systematic differences in the number & way participants are lost from a study between study groups