There are many ways to screen:
"During the past two weeks how much have you been bothered by the following problems:
Items scored as mild or greater may warrant further assessment
A score of 3 or greater on items 1 and 2 considered positive screen for anxiety
A score of 3 or greater on items 3 and 4 is considered positive screen for depression
(if so consider going to the Ottawa Depression Algorithm)
If you have a high suspicion of anxiety, consider simply using the GAD-7, which will allow for screening as well as provide an assessment of severity.