20. You Can Iterate!

The concept of iterating isn't that applicable for clinical trials given the rigor involved in their planning. But, theoretically, the following situations could arise that require iteration:

• Maybe you (as the data analyst or data scientist on the clinical trial research team) realized your statistical power calculations were wrong, and you needed to recruit more patients to make your study statistically significant. You'd also have to do revisit gathering in this scenario.
• Maybe you realized you were missing a key piece of patient information, like patient blood type (again, unlikely given the rigor of clinical trials, but mistakes happen) because you discovered new research that related insulin resistance to blood type. You'd also have to do revisit gathering in this scenario.
• Maybe you finished assessing, started cleaning, and spotted another data quality issue. Revisiting assessing to add these assessments to your notes is fine.