Three questions need separate answers

QuestionWhat needs evaluation
Can people be identified?Privacy risks and generation process
Does the dataset resemble reality?Relevant distributions and relationships
Can it answer this research question?Preservation of the specific analytic signal

A dataset can look realistic while failing to preserve an important association. It can also reproduce unusual details too closely if the generation method memorizes source material.

A useful test dataset has a narrower claim

Synthetic records may be valuable for demonstrating a user interface or testing whether software accepts valid formats. Success at that task does not prove that model performance on the synthetic data predicts performance in a real clinic.

Label the intended use clearly.

Ask how the result was checked

The generation method, source data, privacy evaluation, and utility tests all matter. A vendor's use of the word “synthetic” is not a complete explanation.

For an analysis, inspect the relationships that drive the conclusion, including rare groups and missingness patterns. For a privacy decision, use an appropriate assessment rather than visual inspection of a few rows. A convincing-looking patient table can conceal both scientific limitations and disclosure risks that are not visible in the example records.