Post hoc analysis refers to what practice?

• A. Interim data monitoring
• B. Pre-planned subgroup analysis
• C. Creating new hypotheses after data collection based on observed distributions
• D. Meta-analysis

Answer: (C)

Post hoc analysis is exploratory work done after data collection, where you look for patterns in the data and generate new hypotheses based on what you observe. This often involves examining distributions or unexpected findings and proposing ideas to test in future studies. Because these hypotheses arise from the data at hand, they are more susceptible to chance findings, so they’re typically viewed as hypothesis-generating rather than confirmatory and should be validated in separate data.

This best fits the idea of creating new hypotheses after seeing the collected data, rather than strategies used during the trial or methods that combine results from multiple studies. Interim data monitoring focuses on safety and efficacy checks during the trial; pre-planned subgroup analysis is an analysis you commit to before collecting data; meta-analysis pools results across different studies.