I am having a report written on very complex EHR data where the data needed comes from different formats, from different locations. I need to choose a sample from about 20,000 accounts to manually review to show how accurate the report is.
What is the minimum sample size I would need? Do I calculate this statistically, or do I use a general business rule of n=30? And how can I say how accurate the report is based off of my sample size and the results?