REDCap saves the raw value (also called the choice number: 1,2,3,4), not the label, when saving the data for a field. That means if you change the label, or renumber labels, you can profoundly change the meaning of an answer for all existing records. Do not change a raw value/label pair in production projects. Minor changes to a label alone, such as fixing typos, is ok.
Here is a radio button question, asking survey respondents to select their favorite flavor of ice cream:
But what if you want to add an option, and still keep a list in alphabetical order? The option numbers do not need to be in numeric order; they just need to be unique.
- Increment the highest existing choice number in the question.
- Add the new option with that choice number in its preferred place in the list.
DO NOT DO THIS:
This is the wrong way to add a new choice such as "Mocha". All of the records that had "Strawberry" as the favorite ice cream would have their answer converted to "Mocha". Likewise, all of the "Vanilla" answers would be converted to "Strawberry". This would have a huge negative impact on the project's data integrity.