Statistical Analysis Flashcards
7 cards from real CCDM practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Statistical Analysis flashcards as text
Which sensitivity analysis approach tests whether study conclusions hold when missing data are assumed to be Missing Not at Random (MNAR)?
Answer: Pattern mixture models or tipping point analysis
Pattern mixture models and tipping point analyses explore how conclusions change under MNAR assumptions to assess robustness of primary results.
What is the purpose of a Q-Q (quantile-quantile) plot in clinical data analysis?
Answer: To assess whether a dataset follows a specified theoretical distribution such as normal
A Q-Q plot compares the quantiles of observed data against those of a theoretical distribution; points falling on a straight line indicate a good fit.
In a two-period, two-sequence crossover trial, which statistical effect must be tested before interpreting treatment differences?
Answer: Carryover (sequence-by-period interaction) effect
A significant carryover effect in crossover trials means Period 1 treatment influences Period 2 outcomes, invalidating the within-subject comparison.
The intraclass correlation coefficient (ICC) is most commonly used in clinical trials to quantify:
Answer: The degree of agreement between raters or reliability of repeated measurements
ICC measures the proportion of total variance attributable to between-subject variability, reflecting rater reliability or measurement consistency.
When a clinical trial reports a statistically significant result but a very small effect size, the most appropriate interpretation is:
Answer: Statistical significance does not guarantee clinical relevance; the effect size must be evaluated
Large sample sizes can detect trivially small differences as statistically significant; effect size measures (e.g., Cohen's d, odds ratio) contextualize clinical importance.
Which regression diagnostic is used to identify observations that have an undue influence on the estimated regression coefficients?
Answer: Cook's distance
Cook's distance measures the influence of each observation on all fitted values; high values indicate potentially influential or leverage points.
In adaptive trial designs, what is an 'interim look' primarily used for?
Answer: Assessing pre-specified criteria to modify the trial (e.g., sample size, dose selection) while preserving Type I error control
Planned interim looks in adaptive designs allow pre-specified modifications based on accumulating data while controlling the overall error rate through group sequential methods.