Perhaps you should try some spelling variations:
decrease comprehension » disease comprehension (Expand search), discourse comprehension (Expand search), sentence comprehension (Expand search)
comprehension test » compression test (Expand search), comprehension of (Expand search), comprehension and (Expand search)
decrease pain » decreases pain (Expand search), decrease in (Expand search), decreased brain (Expand search)
pain decrease » can decrease (Expand search), strain decrease (Expand search), taping decrease (Expand search)
decrease the » decreases the (Expand search), decrease in (Expand search), decrease of (Expand search)
the decrease » to decrease (Expand search), and decrease (Expand search)
decrease at » decrease akt (Expand search), decrease and (Expand search), decrease in (Expand search)
at decrease » rate decrease (Expand search), that decrease (Expand search), and decrease (Expand search)

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "(( decrease at decrease the decrease ) OR ( decrease pain decrease comprehension test ))~".
• Adding a wildcard symbol may retrieve word variants: (( decrease at decrease the decrease ) OR ( decrease pain decrease comprehension test ))*.