What is the rationale of collecting social demographic data? Will that violate the privacy rule?

You are welcome.

Thank you so much for the explanation.

Social demographic data usually serves as control variables. In statistical analysis, if we want to rule out the impact of the social demographic influence and test the effectiveness of a certain intervention, we need to collect these background information. Importantly, we cannot leak out these private data and need to make sure the information is strictly kept for internal use only.