observational

They also analyzed real-world observational data and compared results with other climate models for validation.

The various studies are mainly observational and could be skewed by confounding factors—people who are healthy for other reasons could use stairs more, for example.

Although these results are from an observational study and require confirmation through a randomized clinical trial, researchers emphasize their potential importance.

It was observational rather than a randomized comparison of drugs and surgery, and it did not focus exclusively on the newest and most effective GLP-1 medicines.

Together, these assets will form an unprecedented observational network.