A group of nurses wishes to explore the effectiveness of a new treatment approach for increasing activity tolerance among COVID-19 patients. As a member of your agency’s research and practice committee, you review their proposal. They describe how they will use collected demographic data, vital signs, and pulse oximetry readings to track the number of minutes each patient can ambulate.

They propose to collect the following patient data: gender, ethnicity, religion, diagnosis, age measured in decade categories (i.e., 0–10, 11–20, 21–30, 31–40), and name of medications currently taken. What feedback can you give to them about their choice of variables and proposed statistical manipulation?