Representative quotes
	I think to have only one data extractor, no matter how experienced that person is, is problematic. (Methodologist #4)
	I don't know really whether it's acceptable, but I'm not a big fan of only one reviewer. And because sometimes, especially in the field of diagnostics, it's more difficult. It's something more difficult to see what the exact patient population is, which can differ a lot within the diagnostic field. (Information Specialist #2)
	You can also choose a middle route so that the data extraction is done by only one reviewer but checked by another person independently. (Methodologist #1)