Is participation in a medical clinical trial considered "providing a service" to a research study? The dialog for the 1099-MiSC form asks this question?

When I enter the amount I received for participating in a medical clinical trial in the form 1099-MISC dialog, I get prompted for a series of questions. When I answer "yes" to "Did I participate in a research study", I get prompted to answer a follow-up question asking if I provided a service? Would giving blood and other activities associated with clinical trial participation be considered "providing a service?